2BQWU-DS3Doorbell Chime

Hangzhou Huacheng Software Technology Co., Ltd. 15th Floor, Building 3, No. 582, Liye Road, Changhe Street, Binjiang District, Hangzhou, China Rev 1/26/2023 Federal Communications Commission Authorization and Evaluation Division 7435 Oakland Mills Road Columbia, MD 21046 USA Date: 04-14-2026 Ref: Attestation Statements Part 2.911(d)(5)(i) Filing FCC ID: 2BQWU-DS3 [Hangzhou Huacheng Software Technology Co., Ltd.] (“the applicant”) certifies that the equipment for which authorization is sought is not “covered” equipment prohibited from receiving an equipment authorization pursuant to section 2.903 of the FCC rules. [Hangzhou Huacheng Software Technology Co., Ltd.] (“the applicant”) certifies that the equipment for which authorization is sought does not include cybersecurity or anti-virus software produced or provided by Kaspersky Lab, Inc. or any of its successors and assignees, including equipment with integrated Kaspersky Lab, Inc. (or any of its successors and assignees) cybersecurity or anti-virus software pursuant to DA-24-886 and KDB 986446 D01 Covered Equipment Guidance section B(2a). Device is inherently compliant based on hardware limitations or software controls. or A Software Bill of Materials (SBOM) is provided to the TCB for review, and The end-user or third parties cannot install additional software on this device. Sincerely, Company Officer: Alex.Xu Telephone Number: 8619957195013 Email: [email protected] Hangzhou Huacheng Software Technology Co., Ltd. 15th Floor, Building 3, No. 582, Liye Road, Changhe Street, Binjiang District, Hangzhou, China Rev 1/26/2023 Federal Communications Commission Authorization and Evaluation Division 7435 Oakland Mills Road Columbia, MD 21046 USA Date: 04-14-2026 Ref: Attestation Statements Part 2.911(d)(5)(ii) Filing FCC ID: 2BQWU-DS3 [Hangzhou Huacheng Software Technology Co., Ltd.] (“the applicant”) certifies that, as of the date of the filing of the application, the applicant is not identified on the Covered List (as a specifically named entity or any of its subsidiaries or affiliates) as an entity producing “covered” equipment. Sincerely, Company Officer: Alex.Xu Telephone Number: 8619957195013 Email: [email protected]

Rev 1/26/2023 Hangzhou Huacheng Software Technology Co., Ltd. 15th Floor, Building 3, No. 582, Liye Road, Changhe Street, Binjiang District, Hangzhou, China Federal Communications Commission Authorization and Evaluation Division 7435 Oakland Mills Road Columbia, MD 21046 USA Date: 04-14-2026 Ref: Attestation Statements Part 2.911(d)(7) Filing FCC ID: 2BQWU-DS3 Applicant FRN: 0037281912 [Hangzhou Huacheng Software Technology Co., Ltd.] (“the applicant”) certifies that, as of the date of the filing of the application, [FCC US Agent, LLC] is our designated U.S. agent for service of process for the above referenced FCC ID. [Hangzhou Huacheng Software Technology Co., Ltd.] accepts to maintain an agent for no less than one year after the grantee has terminated all marketing and importation or the conclusion of any Commission-related proceeding involving the equipment. [FCC US Agent, LLC] accepts, as of the date of the filing of the application, the obligation of the designated U.S. agent for service of process for the above referenced FCC ID. Designated U.S. Agent Information: Name: FCC US Agent, LLC U.S. Agent FRN: 0033402884 Address: 3722 Illinois Avenue, Saint Charles, IL, 60174, USA Contact Person: Tim Payne Tel.: 708-571-3148 Email: [email protected] Sincerely, Hangzhou Huacheng Software Technology Co., Ltd. FCC US Agent, LLC Alex Xu Tim Payne [Insert U.S. Agent signature]

Hangzhou Huacheng Software Technology Co., Ltd. 15th Floor, Building 3, No. 582, Liye Road, Changhe Street, Binjiang District, Hangzhou, China WIFI Channel 12 ,13 and 14 Declaration Letter We declare the equipment identified below with regards to Channel 12,13 and 14 capabilities for FCC ID: 2BQWU-DS3 Declaration Product hardware does not have the capability to operate on Channel 12,13 and 14. Product hardware has the capability to operate on Channel 12 ,13 and 14. However, these three channels will be disabled via software and will not be accessible to user. Product hardware has the capability to operate on Channel 12 ,13 and 14. However, all the operated channels can’t be changed in the RF parameter via software. All channels have complied with all of the requirements sets out in FCC Part 15.247. Product hardware has the capability to operate on WiFi Channel 12 ,13 and 14, and meets the requirements of KDB 594280 D01 v02r01. Please note: 1.) By default, this device operates in a mode that is compliant with the U.S. requirements. 2.) This device will also use supplemental information such as geo-location data to determine that it is operating outside the U.S., if necessary, to change its power. Such supplemental data will be derived from the following: Global Navigation Satellite System (GNSS)7 sensors in the device Mobile Country Code (MCC),8 or MCC with a Mobile Network code (MNC), received from a CMRS9 carrier and received directly by a receiver on the device Country information derived from multiple adjacent access points (for example using IEEE Std 802.11d provisions) may be permitted on case-by-case basis Other suitable geo-location data based on IP addresses or other reliable source. Company Officer: Alex.Xu Telephone Number: 8619957195013 Date: 2026/4/14

Hangzhou Huacheng Software Technology Co., Ltd. 15th Floor, Building 3, No. 582, Liye Road, Changhe Street, Binjiang District, Hangzhou, China Federal Communications Commission Authorization and Evaluation Division 7435 Oakland Mills Road Columbia, MD 21046 Date: 04-14-2026 SUBJECT: FCC Application for FCC ID: 2BQWU-DS3 To Whom It May Concern: We, the undersigned, hereby authorize Hong Yan at TÜV SÜD Certification and Testing (China) Co., Ltd. Shanghai Branch on our behalf, to apply to the Federal Communications Commission on our equipment. Any and all acts carried out by Yu Anlu on our behalf shall have the same effect as acts of our own. This is to advise that we are in full compliance with the Anti- Drug Abuse Act. We, the applicant, are not subject to a denial of federal benefits pursuant to Section 5301 of the Anti-Drug Act of 1988, 21 USC853a, and no party to the application is subject to a denial of federal benefits pursuant to that section. Regards, Company Officer: Alex.Xu Telephone Number: 8619957195013 Email: [email protected]

Hangzhou Huacheng Software Technology Co., Ltd. 15th Floor, Building 3, No. 582, Liye Road, Changhe Street, Binjiang District, Hangzhou, China Rev 11/20/07 Federal Communications Commission Authorization and Evaluation Division Confidentiality Request regarding application for certification of FCC ID: 2BQWU-DS3 Pursuant to Sections 0.457 and 0.459 of the Commission’s Rules, we hereby request confidential treatment of information accompanying this application as outlined below: Exhibit Type File Name Block Diagram Schematics Operational Description PCB Block Diagram Schematics Operational Description PCB The above materials contain trade secrets and proprietary information not customarily released to the public. The public disclosure of these materials may be harmful to the applicant and provide unjustified benefits to its competitors. The applicant understands that pursuant to Section 0.457 of the Rules, disclosure of this application and all accompanying documentation will not be made before the date of the Grant for this application. Pursuant to DA04-1705 June 15, 2004 of the Commission’s public notice, we also request temporary confidential treatment of information accompanying this application as outlined below: Exhibit Type File Name Internal Photos Setup photos Manual Internal Photos Setup photos Manual Number of days: 180 days Sincerely, Company Officer: Alex.Xu Telephone Number: 8619957195013 Date: 2026/4/14

Appendix EP Photographs of EUT Product: Doorbell Chime Brand Name: imou Type Identification: DS3 Page 1 of 6 Appendix EP Photographs of EUT Product: Doorbell Chime Brand Name: imou Type Identification: DS3 Page 2 of 6 Appendix EP Photographs of EUT Product: Doorbell Chime Brand Name: imou Type Identification: DS3 Page 3 of 6 Appendix EP Photographs of EUT Product: Doorbell Chime Brand Name: imou Type Identification: DS3 Page 4 of 6 Appendix EP Photographs of EUT Product: Doorbell Chime Brand Name: imou Type Identification: DS3 Page 5 of 6 Accessory Appendix EP Photographs of EUT Product: Doorbell Chime Brand Name: imou Type Identification: DS3 Page 6 of 6 Label Location

Report No: 709502511486-00 EMC_SHA_F_R_02.06E TÜV SÜD Certification and Testing (China) Co., Ltd. Shanghai Branch 3-13, No.151, Heng Tong Road, Shanghai, 200070, P.R. China Phone: +86 21 61410123, Fax:+86 21 61408600 Page 1 of 2 Rev. 23.00 MPE Calculation Applicant: Hangzhou Huacheng Software Technology Co., Ltd. Address: 15th Floor, Building 3, No. 582, Liye Road, Changhe Street, Binjiang District, Hangzhou, China Product: Doorbell Chime FCC ID: 2BQWU-DS3 Model No.: DS3 Reference RF report # 6128626009501 According to subpart 15.247(i) and subpart §1.1307(b)(1), systems operating under the provisions of this section shall be operated in a manner that ensures that the public is not exposed to radio frequency energy level in excess of the Commission’s guidelines. Limits for Maximum Permissible Exposure (MPE) (§1.1310, §2.1091) (B) Limits for General Population/Uncontrolled Exposure Frequency Range (MHz) Electric Field Strength (V/m) Magnetic Field Strength (A/m) Power Density (mW/cm 2 ) Averaging Time (minutes) 0.3–1.34 614 1.63 *(100) 30 1.34–30 824/f 2.19/f *(180/f²) 30 30–300 27.5 0.073 0.2 30 300–1,500 / / f/1500 30 1,500–100,000 / / 1.0 30 f = frequency in MHz; * = Plane-wave equivalent power density; According to §1.1310 and §2.1091 RF exposure is calculated. Calculated Formulary: Predication of MPE limit at a given distance S = PG/4πR² = power density (in appropriate units, e.g. mW/cm 2 ); P = power input to the antenna (in appropriate units, e.g., mW); G = power gain of the antenna in the direction of interest relative to an isotropic radiator, the power gain factor, is normally numeric gain; R = distance to the center of radiation of the antenna (appropriate units, e.g., cm); Report No: 709502511486-00 EMC_SHA_F_R_02.06E TÜV SÜD Certification and Testing (China) Co., Ltd. Shanghai Branch 3-13, No.151, Heng Tong Road, Shanghai, 200070, P.R. China Phone: +86 21 61410123, Fax:+86 21 61408600 Page 2 of 2 Rev. 23.00 Calculated Data: PCB antenna Maximum peak output power at antenna input terminal (dBm): 22.61 Maximum peak output power at antenna input terminal (mW): 182.39 Output power tune-up tolerance (dB) ±1.0 Maximum tune-up conducted power(dBm): 23.61 Maximum tune-up conducted power(mW): 229.61 Prediction distance (cm): 20 Antenna Gain, typical (dBi): 4.59 Maximum Antenna Gain (numeric): 2.8774 The worst case is power density at predication frequency at 20 cm (mW/cm 2 ): 0.13144 MPE limit for general population exposure at prediction frequency (mW/cm 2 ): 1.00 Note: The maximum tune-up conducted power (23.61 dBm) was declared by the manufacturer. The max power density 0.13144 (mW/cm2) < 1 (mW/cm2) Result: Compliant - TÜV SÜD Certification and Testing (China) Co., Ltd. Shanghai Branch Reviewed by: Prepared by: _____________________ _____________________ Hui TONG Wenqiang LU EMC Section Manager EMC Project Engineer Date: 2026-04-10 Date: 2026-04-10 -------------------------------------------------------End of Test Report-------------------------------------------------------

DongguanYoubiElectronicsCo.,LTDHangzhouYoubigeElectronicsCo.,LTDShenzhenYoubiElectronicsCo.,LTD Room101,Building2,No.9,Room106,Building3,LetongSciencePark,Room106,BuildingA,XinzhengIndustrialPark, XinfaRoad,LinVillage,TangxiaTownNo.500QiuyiRoad,BinjiangDistrict57LiuxianRoad,Bao'anDistrict,Shenzhen Tel:+86-769-81777126Website：www.ubuant.com 1 / 10 Antenna Specification PRODUCT NAME: 2.4/5.8G W58 White Antenna L=32mm+terminal UBP/N:UB02C40W2D5184AREV:D RevisionRevisorDateRevisionRecord V-AWan.Bin2024年03月12日Newissue V-BWan.Bin2024年09月12日Changepackaging V-CKangjun.Xu2024年12月06日ChangePlasticcardpoint V-DKangjun.Xu2024年12月23日ChangePacktype MANUFACTURER SIGNATURE CUSTOMER SIGNATURE CHECKEDBY: Kangjun.Xu APPROVEDBY: Wenqiang.Xiong DATE:2026/03/06 DongguanYoubiElectronicsCo.,LTDHangzhouYoubigeElectronicsCo.,LTDShenzhenYoubiElectronicsCo.,LTD Room101,Building2,No.9,Room106,Building3,LetongSciencePark,Room106,BuildingA,XinzhengIndustrialPark, XinfaRoad,LinVillage,TangxiaTownNo.500QiuyiRoad,BinjiangDistrict57LiuxianRoad,Bao'anDistrict,Shenzhen Tel:+86-769-81777126Website：www.ubuant.com 2/10 Contents 1Specification-------------------------------------------------------------------------------------- 2AntennaDimension------------------------------------------------------------------------------ 3MatchingCircuit------------------------------------------------------------------------------------- 4ElectricalTest------------------------------------------------------------------------------------- 4.1Method------------------------------------------------------------------------------------- 4.2Device-------------------------------------------------------------------------------------- 4.3TestConfiguration------------------------------------------------------------------------ 4.4PassiveTest-------------------------------------------------------------------------------- DongguanYoubiElectronicsCo.,LTDHangzhouYoubigeElectronicsCo.,LTDShenzhenYoubiElectronicsCo.,LTD Room101,Building2,No.9,Room106,Building3,LetongSciencePark,Room106,BuildingA,XinzhengIndustrialPark, XinfaRoad,LinVillage,TangxiaTownNo.500QiuyiRoad,BinjiangDistrict57LiuxianRoad,Bao'anDistrict,Shenzhen Tel:+86-769-81777126Website：www.ubuant.com 3/10 1Specification Specification P/N Frequency DualbandWi-Fiantenna2400~2500&5150~5850MHz AntennaType Dipole Dimension 12.0*82.23*17.26mm Impedance 50Ω Polarization Linear VSWR <1.92 AxialRatio notinvolved Efficiency 55~65% Gain 5.02dbi RadiationPattern Omni-directional Connection IPEX1 LineType RF1.13 LineLoss 0.5dB·m -1 @1GHz，1dB·m -1 @3GHz，3dB·m -1 @6GHz PowerHandling 1W Operating Temperature -20~70°C Storagetemperature -20~50°C DongguanYoubiElectronicsCo.,LTDHangzhouYoubigeElectronicsCo.,LTDShenzhenYoubiElectronicsCo.,LTD Room101,Building2,No.9,Room106,Building3,LetongSciencePark,Room106,BuildingA,XinzhengIndustrialPark, XinfaRoad,LinVillage,TangxiaTownNo.500QiuyiRoad,BinjiangDistrict57LiuxianRoad,Bao'anDistrict,Shenzhen Tel:+86-769-81777126Website：www.ubuant.com 4/10 2AntennaDimension DongguanYoubiElectronicsCo.,LTDHangzhouYoubigeElectronicsCo.,LTDShenzhenYoubiElectronicsCo.,LTD Room101,Building2,No.9,Room106,Building3,LetongSciencePark,Room106,BuildingA,XinzhengIndustrialPark, XinfaRoad,LinVillage,TangxiaTownNo.500QiuyiRoad,BinjiangDistrict57LiuxianRoad,Bao'anDistrict,Shenzhen Tel:+86-769-81777126Website：www.ubuant.com 5/10 3.MatchingCircuit TheComponentsofMatchingCircuit PositionDescripitionTolerance 1-- 20Ω- 3-- DongguanYoubiElectronicsCo.,LTDHangzhouYoubigeElectronicsCo.,LTDShenzhenYoubiElectronicsCo.,LTD Room101,Building2,No.9,Room106,Building3,LetongSciencePark,Room106,BuildingA,XinzhengIndustrialPark, XinfaRoad,LinVillage,TangxiaTownNo.500QiuyiRoad,BinjiangDistrict57LiuxianRoad,Bao'anDistrict,Shenzhen Tel:+86-769-81777126Website：www.ubuant.com 6/10 4ElectricalTest 4.1Method NameParameterMethodStandardno. MobileCommunication antenna VSWR Genericspecificationfor antennasusedinthe mobilecommunications GB/T9410-2008 Antennagain Radiationpattern AntennaperformanceRadiationefficiency IEEEStandardTest ProceduresforAntennas ANSI/IEEEStd 149-1979 4.2Device EquipmentManufacturerModelNo.SerialNo.LastCal.DueDate NetworkAnalyzerAgilentE5071CMY463159962025.08.252026.08.24 RadioCommunication Tester ROHDE&SCHWARZ CMW500 0002K50-100 844 2025.08.252026.08.24 4.3TestConfiguration DongguanYoubiElectronicsCo.,LTDHangzhouYoubigeElectronicsCo.,LTDShenzhenYoubiElectronicsCo.,LTD Room101,Building2,No.9,Room106,Building3,LetongSciencePark,Room106,BuildingA,XinzhengIndustrialPark, XinfaRoad,LinVillage,TangxiaTownNo.500QiuyiRoad,BinjiangDistrict57LiuxianRoad,Bao'anDistrict,Shenzhen Tel:+86-769-81777126Website：www.ubuant.com 7/10 4.4PassiveTest 4.4.1ReturnLoss&VSWR Frequency（MHz）24002450250051505850 ReturnLoss（dB）-10.77-20.11-11.24-10.41-10.54 DongguanYoubiElectronicsCo.,LTDHangzhouYoubigeElectronicsCo.,LTDShenzhenYoubiElectronicsCo.,LTD Room101,Building2,No.9,Room106,Building3,LetongSciencePark,Room106,BuildingA,XinzhengIndustrialPark, XinfaRoad,LinVillage,TangxiaTownNo.500QiuyiRoad,BinjiangDistrict57LiuxianRoad,Bao'anDistrict,Shenzhen Tel:+86-769-81777126Website：www.ubuant.com 8/10 4.4.2Efficiency&Gain Frequency/MHzEfficiency/dBEfficiency/%Gain/dBi 2400-1.4471.784.59 2410-1.5669.823.84 2420-1.3273.793.93 2430-1.4272.112.98 2440-1.2375.342.7 2450-1.1177.452.11 2460-1.2574.991.72 2470-0.9680.172.06 2480-1.1876.211.51 2490-1.0279.071.44 2500-1.3573.281.26 5150-1.5869.54.96 5200-1.4471.785.02 5250-1.3772.954.95 5300-1.1676.564.71 5350-1.1676.563.94 5400-0.9480.544.16 5450-0.8382.63.52 5500-0.8482.413.31 5550-0.7683.953.58 5600-0.7184.923.76 5650-0.7883.563.25 5700-0.8282.793.28 5750-0.8182.993.34 5800-0.9280.913.24 5850-1.3373.622.67 DongguanYoubiElectronicsCo.,LTDHangzhouYoubigeElectronicsCo.,LTDShenzhenYoubiElectronicsCo.,LTD Room101,Building2,No.9,Room106,Building3,LetongSciencePark,Room106,BuildingA,XinzhengIndustrialPark, XinfaRoad,LinVillage,TangxiaTownNo.500QiuyiRoad,BinjiangDistrict57LiuxianRoad,Bao'anDistrict,Shen…

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Report Number: 6128626009503 Page 23 of 127 Appendix A. Test Equipment Radiated Emission Measurement Equipment Manufacturer Model No. Serial No. Cal. Date Cal. Interval Spectrum Analyzer R&S FSV3044 101348 2025-07-29 1 Year Spectrum Analyzer R&S ESR 7 102600 2025-08-22 1 Year Horn (18-40G) RF SPIN DRH0844 LE2C01A0844 2025-12-19 1 Year Horn (1-18G) RF SPIN DRH18-E 211218A18EN 2025-11-05 1 Year Bi-Log Antenna Schwarzbeck VULB 9168 01496 2026-02-11 1 Year Preamplifier (1-18G) SGH SGH118-HS 20230214-5 2025-04-10 1 Year Preamplifier (18-40G) SGH SGH184 20230214-8 2025-04-10 1 Year Preamplifier (30M-1G) SGH SGH0301 20230214-4 2025-04-24 1 Year Test Software Audix e3 221118, V9 N/A N/A AC Power Line Conducted Emission Equipment Manufacturer Model No. Serial No. Cal. Date Cal. Interval EMI Receiver R&S ESR 7 102599 2025-08-11 1 Year LISN R&S ENV216 101517 2025-10-31 1 Year Test Software Audix e3 221118, V9 NCR NCR. RF Conducted Measurement Equipment Manufacturer Model No. Serial No. Cal. Date Cal. Interval Spectrum Analyzer Keysight N9010B MY63440384 2025-07-11 1 Year Power Sensor Anritsu MA24408A 12778 2026-03-12 1 Year Test Software Anritsu MA24400A USB Peak Power Sensor 1.1.0.0 NCR NCR. Test Software Keysight IOT0047A 24.11.25.17 NCR NCR. *: The calibrations of the above equipment are traceable to NIST or equivalent standards of the reference organizations. Report Number: 6128626009503 Page 24 of 127 Appendix B. Duty Cycle 802.11b *Duty cycle = 1 *If duty cycle of test signal is ≥ 98%, duty factor is not required. *If duty cycle of test signal is < 98%, duty factor shall be considered. 1Mbps Duty On (ms): - Duty Cycle = Ton / (Ton + Toff) Duty OnOff (ms): - Duty Cycle (%): 100 VBW (Hz): 10 Report Number: 6128626009503 Page 25 of 127 802.11g *Duty cycle = 1 *If duty cycle of test signal is ≥ 98%, duty factor is not required. *If duty cycle of test signal is < 98%, duty factor shall be considered. 6Mbps Duty On (ms): - Duty Cycle = Ton / (Ton + Toff) Duty OnOff (ms): - Duty Cycle (%): 100 VBW (Hz): 10 Report Number: 6128626009503 Page 26 of 127 802.11n20 *Duty cycle =1 *If duty cycle of test signal is ≥ 98%, duty factor is not required. *If duty cycle of test signal is < 98%, duty factor shall be considered MCS0 Duty On (ms): - Duty Cycle = Ton / (Ton + Toff) Duty OnOff (ms): - Duty Cycle (%): 100 VBW (Hz): 10 Report Number: 6128626009503 Page 27 of 127 802.11ax20 *Duty cycle = 1 *If duty cycle of test signal is ≥ 98%, duty factor is not required. *If duty cycle of test signal is < 98%, duty factor shall be considered MCS0 Duty On (ms): - Duty Cycle = Ton / (Ton + Toff) Duty OnOff (ms): - Duty Cycle (%): 100 VBW (Hz): 10 Report Number: 6128626009503 Page 28 of 127 Appendix C. Peak Conducted Output Power Peak Output Power <11b> Channel Channel Frequency Peak Output Power Average Output Power Power Setting Limit(dBm) (MHz) (dBm) (mW) (dBm) (mW) Low Channel 2412 15.04 31.915379 12.77 18.923436 -5 30 Middle Channel 2437 15.09 32.284941 12.81 19.098533 -5 30 High Channel 2462 14.83 30.408850 12.34 17.139573 -5 30 <11g> Channel Channel Frequency Peak Output Power Average Output Power Power Setting Limit(dBm) (MHz) (dBm) (mW) (dBm) (mW) Low Channel 2412 22.16 164.437172 11.79 15.100802 -4 30 Middle Channel 2437 22.61 182.389570 12.41 17.418069 -4 30 High Channel 2462 22.59 181.551566 12.37 17.258379 -4 30 Report Number: 6128626009503 Page 29 of 127 Peak Output Power <11n20 > Channel Channel Frequency Peak Output Power Average Output Power Power Setting Limit(dBm) (MHz) (dBm) (mW) (dBm) (mW) Low Channel 2412 20.04 100.925289 10.59 11.455129 -6 30 Middle Channel 2437 19.97 99.311605 10.51 11.246050 -6 30 High Channel 2462 19.56 90.364947 10.14 10.327614 -6 30 <11ax20 > Channel Channel Frequency Peak Output Power Average Output Power Power Setting Limit(dBm) (MHz) (dBm) (mW) (dBm) (mW) Low Channel 2412 20.84 121.338885 10.62 11.534533 -6 30 Middle Channel 2437 20.76 119.124201 10.55 11.350108 -6 30 High Channel 2462 20.37 108.893009 10.18 10.423174 -6 30 Report Number: 6128626009503 Page 30 of 127 Appendix D. Bandwidth Measurement Only the worst-case plots are presented herein. all of which were found to be in compliance with the rule. 6dB Bandwidth <11b> Channel Channel Frequency 6dB Bandwidth > 0.5 MHz (MHz) (MHz) Low Channel 2412 9.900 0.5 Middle Channel 2437 10.100 0.5 High Channel 2462 10.100 0.5 Report Number: 6128626009503 Page 31 of 127 6dB Bandwidth <11g> Channel Channel Frequency 6dB Bandwidth > 0.5 MHz (MHz) (MHz) Low Channel 2412 16.350 0.5 Middle Channel 2437 16.350 0.5 High Channel 2462 16.350 0.5 Report Number: 6128626009503 Page 32 of 127 6dB Bandwidth <11n20> Channel Channel Frequency 6dB Bandwidth > 0.5 MHz (MHz) (MHz) Low Channel 2412 17.600 0.5 Middle Channel 2437 17.600 0.5 High Channel 2462 17.600 0.5 Report Number: 6128626009503 Page 33 of 127 6dB Bandwidth <11ax20> Channel Channel Frequency 6dB Bandwidth > 0.5 MHz (MHz) (MHz) Low Channel 2412 19.000 0.5 Middle Channel 2437 19.000 0.5 High Channel 2462 19.000 0.5 Report Number: 6128626009503 Page 34 of 127 99% Bandwidth <11b> Channel Channel Frequency 99% Bandwidth (MHz) (MHz) Low Channel 2412 14.919 Middle Channel 2437 14.936 High Channel 2462 14.940 Report Number: 6128626009503 Page 35 of 127 99% Bandwidth <11g> Channel Channel Frequency 99% Bandwidth (MHz) (MHz) Low Channel 2412 16.990 Middle Channel 2437 16.990 High Channel 2462 16.988 Report Number: 6128626009503 Page 36 of 127 99% Bandwidth <11n20> Channel Channel Frequency 99% Bandwidth (MHz) (MHz) Low Channel 2412 18.167 Middle Channel 2437 18.171 High Channel 2462 18.170 Report Number: 6128626009503 Page 37 of 127 99% Bandwidth <11ax20> Channel Channel Frequency 99% Bandwidth (MHz) (MHz) Low Channel 2412 19.103 Middle Channel 2437 19.105 High Channel 2462 19.106 Report Number: 6128626009503 Page 38 of 127 Appendix E Peak Power Spectral Density Only the worst-case plots are presented herein. Power Density <11b> Channel Channel Frequency Power Density Limit (dBm/3kHz) (MHz) …

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TÜ V SÜ D Asia Ltd., Taiwan Branch 7F., No. 37, Sec. 2, Zhongyang S. Rd., Beitou District, Taipei City, 11270, Taiwan (R.O.C.) Phone: + 886 2 2898-6818 Fax: + 886 2 2895-1598 Revision: 1.1 Effective: 2026-01-28 Page 1 of 127 Partial use/copy of this test report is not permitted. Only the entire report can be reproduced. FCC Test Report Report Number : 6128626009503 Applicant : Hangzhou Huacheng Software Technology Co., Ltd. Product : Doorbell Chime Brand : imou Model : DS3 FCC ID : 2BQWU-DS3 Applicable Standard: FCC Subpart 15.247 RESPONSIBLE FOR NAME SIGNATURE DATE Approved By Jack Chang 2026-04-22 Prepared By Ariel Hsu 2026-04-22 Signatures in this approval box have checked this document in line with the requirements of TÜ V SÜ D Product Service control rules. EXECUTIVE SUMMARY TÜ V SÜ D Asia Ltd., reports apply only to the specific samples tested under stated test conditions. Construction of the actual test samples has been documented. It is the manufacturer's responsibility to assure that additional production units of this model are manufactured with identical electrical and mechanical components. The manufacturer/importer is responsible to the Competent Authorities for any modifications made to the production units which result in non-compliance to the relevant regulations. TÜ V SÜ D Asia Ltd. shall have no liability for any deductions, inferences or generalizations drawn by the client or others from TÜ V SÜD Asia Ltd. issued reports. This report is the confidential property of the client. As a mutual protection to our clients, the public and ourselves, extracts from the test report shall not be reproduced except in full without our written approval. Report Number: 6128626009503 Page 2 of 127 Contents 1 General Information ....................................................................................................................3 1.1 Report Modification Record ...........................................................................................................3 1.2 Introduction ....................................................................................................................................3 1.3 Reference Measurement Document .............................................................................................4 1.4 Brief Summary of Test Results .....................................................................................................4 2 General EUT Information ............................................................................................................5 2.1 Technical Specification of EUT .....................................................................................................5 2.2 Antenna List ..................................................................................................................................6 3 EUT Setup Configuration ...........................................................................................................7 3.1 Block Diagram ...............................................................................................................................7 3.2 Support Equipment ........................................................................................................................9 3.3 Support Cable(s) ...........................................................................................................................9 3.4 Channel list and Power Setting .................................................................................................. 10 3.5 Test Configuration ...................................................................................................................... 11 3.6 Test Condition ............................................................................................................................ 12 4 Technical Requirements .......................................................................................................... 13 4.1 Duty Cycle .................................................................................................................................. 13 4.2 Peak Conducted Output Power .................................................................................................. 14 4.3 Bandwidth Measurement ........................................................................................................... 15 4.4 Peak Power Spectral Density ..................................................................................................... 16 4.5 Conducted Spurious Emission ................................................................................................... 17 4.6 Radiated Spurious Emissions and Band Edges ........................................................................ 18 4.7 AC Power Line Conducted Emission Measurement .................................................................. 21 5 Measurement Uncertainty ....................................................................................................... 22 Appendix A. Test Equipment ................................................................................................................... 23 Appendix B. Duty Cycle ............................................................................................................................ 24 Appendix C. Peak Conducted Output Power ......................................................................................... 28 Appendix D. Bandwidth Measurement ................................................................................................... 30 Appendix E Peak Power Spectral Density .............................................................................................. 38 Appendix F. Conducted Spurious Emission.......................................................................................... 42 Appendix G. Radiated Spurious Emissions and Band Edges ...............................................…

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