2AZI3F55Wireless Doorbell Transmitter

FCC Statement This device complies with part 15 of the FCC rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment. NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: Ь Reorient or relocate the receiving antenna. Ь Increase the separation between the equipment and receiver. Ь Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. Ь Consult the dealer or an experienced radio/TV technician for help. The device has been evaluated to meet general RF exposure requirement. The device can be used in portable exposure condition without restriction.

FCC ID:2AZI3F55 TB-RF-074-1.0 Appendix III EUT External Photographs Photo 1 Appearance of EUT Photo 2 Appearance of EUT FCC ID:2AZI3F55 TB-RF-074-1.0 Photo 3 Appearance of EUT Photo 4 Appearance of EUT FCC ID:2AZI3F55 TB-RF-074-1.0 Photo 5 Appearance of EUT Photo 6 Appearance of EUT

FCC ID:2AZI3F55 TB-RF-074-1.0 Appendix IID Label FCC ID:2AZI3F55 TB-RF-074-1.0 Appendix II ID Label Location

FCC ID:2AZI3F55 TB-RF-074-1.0 Appendix IV EUT Internal Photographs Photo 7 Internal of EUT Photo 8 Appearance of PCB FCC ID:2AZI3F55 TB-RF-074-1.0 Photo 9 Appearance of PCB Photo 10 Appearance of PCB Antenna

Shenzhen Toby Technology Co., Ltd. Report No.: TBR-C-202403-0223-22 Page: 1 of 3 TB-RF-075-1.0 1/F.,Building 6, Rundongsheng Industrial Zone, Longzhu, Xixiang, Bao'an District, Shenzhen, Guangdong, China Tel: +86 75526509301 Fax: +86 75526509195 Maximum Permissible Exposure Evaluation FCC ID:2AZI3F55 1. Client Information Applicant : SHENZHEN KERUI SMART TECHNOLOGY CO., LTD Address : Room 1501, T2, Jinlitong Building, No. 1100, Xingye Road, Xin'an Street, Bao'an District, Shenzhen, Guangdong, China Manufacturer : SHENZHEN KERUI SMART TECHNOLOGY CO., LTD Address : Room 1501, T2, Jinlitong Building, No. 1100, Xingye Road, Xin'an Street, Bao'an District, Shenzhen, Guangdong, China 2. General Description of EUT EUT Name : Wireless Doorbell Transmitter Model(s) No. : F55, M520+F55, M520+F55X2, M520X2+F55, M520X2+F55X2, M520X3+F55X2, M508+F55, M508+F55X2, M508X2+F55, M508X2+F55X2, M508X3+F55X2, M523+F55, M523+F55X2, M523X2+F55, M523X2+F55X2, M523X3+F55X2 Model Difference : All PCB boards and circuit diagrams are the same, the only difference is that appearance color. Product Description : Operation Frequency: 433.92 MHz Antenna Gain: -6.3dBi PCB Antenna Power Supply : DC 3.0V by button cell Software Version : ----- Hardware Version : KR-F55-CE-V1.1-2434 Remark: The antenna gain provided by the applicant, the adapter and verified for the RF conduction test and adapter provided by TOBY test lab. Note: More test information about the EUT please refer the RF Test Report. Report No.: TBR-C-202403-0223-22 Page: 2 of 3 TB-RF-075-1.0 The RF Exposure Evaluation for FCC: SAR Test Exclusion Calculations FCC: According to 447498 D04 Interim General RF Exposure Guidance v01. The SAR-based exemption formula of § 1.1307(b)(3)(i)(B), repeated here as Formula (B.2), applies for single fixed, mobile, and portable RF sources with available maximum time-averaged power or effective radiated power (ERP), whichever is greater, of less than or equal to the threshold P th (mW). This method shall only be used at separation distances from 0.5 cm to 40 cm and at frequencies from 0.3 GHz to 6 GHz (inclusive). P th is given by Formula (B.2). and f is in GHz, d is the separation distance (cm), and ERP 20cm is per Formula (B.1). The example values shown in Table B.2 are for illustration only. Table B.2—Example Power Thresholds (mW) Report No.: TBR-C-202403-0223-22 Page: 3 of 3 TB-RF-075-1.0 Calculations 1. Antenna Gain: PCB Antenna: -6.3dBi. 2. EUT Operation Condition: Software provided by client enabled the EUT to transmit and receive data at lowest, middle and highest channel individually. 3. Exposure Evaluation: Equation from page 18 of OET Bulletin 65, Edition 97-01 S=(PG)/4πR 2 Where S: power density P: power input to the antenna G: power gain of the antenna in the direction of interest relative to an isotropic radiator. R: distance to the center of radiation of the antenna 4. Test Result: EIRP=E-104.8+20logD=67.11-104.8+20log3 = -28.15dBm Frequency (MHz) Measured Power (dBm) Tune up Tolerance ± (dB) Output power (Max. Turn-up Procedure) (mW) Limit (mW) 433.92 -28.15 -28±1 0.002 22 Note: At separation distance of ≤5 mm 5. Conclusion: The measurement results comply with the FCC Limit per 47 CFR 2.1093 for the uncontrolled RF Exposure of mobile device. -----END OF REPORT-----

1 ShenzhenLisyuanCommunicationTechnology Co.,LTD KR-F55Antennatestreport 1.Test Equipment & Condition 1.1 Network Analyzers : KEYSIGHT P5002A 1.2． Communications Test Set: R&S CMW500 1.3 3D Chamber Test System:64Probe testingsystem 03/27/2024 2 ShenzhenLisyuanCommunicationTechnology Co.,LTD 2.Mechanicalinstruction monopole 但单monopole monopole monopoleantenna 03/27/2024 3 ShenzhenLisyuanCommunicationTechnology Co.,LTD 3.Gain&Efficiency&3DPattern FrequencyID Frequency(MHz) 427429431433435437439441 Gain(dBi)-6.5-6.3-6.6-6.3-6.6-6.3-6-6 Efficiency(DB)-9.3-9.3-9.4-9.1-9.3-9.2-8.2-8.5 03/27/2024 4 ShenzhenLisyuanCommunicationTechnology Co.,LTD 4.VSWR 03/27/2024

Shenzhen Toby Technology Co., Ltd. Report No.: TBR-C-202403-0223-21 Page: 1 of 33 TB-RF-074-1.0 1/F.,Building 6, Rundongsheng Industrial Zone, Longzhu, Xixiang, Bao'an District, Shenzhen, Guangdong, China Tel: +86 75526509301 Fax: +86 75526509195 Radio Test Report FCC ID:2AZI3F55 Report No. : TBR-C-202403-0223-21 Applicant : SHENZHEN KERUI SMART TECHNOLOGY CO., LTD Equipment Under Test (EUT) EUT Name : Wireless Doorbell Transmitter Model No. : F55 Series Model No. : Please Refer To Page 5 Brand Name : SECRUI Sample ID : HC-C-202403-0223-02-01 Receipt Date : 2024-03-29 Test Date : 2024-03-29 to 2024-04-11 Issue Date : 2024-04-11 Standards : FCC Part 15, Subpart C (15.231(a)) Test Method : ANSI C63.10:2013 Conclusions : PASS In the configuration tested, the EUT complied with the standards specified above. Tested By : Zkn Zhou Reviewed By : Camille Li Approved By : Ivan Su This report details the results of the testing carried out on one sample. The results contained in this test report do not relate to other samples of the same product. The manufacturer should ensure that all products in series production are in conformity with the product sample detailed in the report. Report No.: TBR-C-202403-0223-21 Page: 2 of 33 TB-RF-074-1.0 Contents CONTENTS ............................................................................................................................................. 2 1. GENERAL INFORMATION ABOUT EUT.............................................................................. 5 1.1 Client Information ................................................................................................................. 5 1.2 General Description of EUT (Equipment Under Test) ................................................... 5 1.3 Block Diagram Showing the Configuration of System Tested ...................................... 7 1.4 Description of Support Units .............................................................................................. 7 1.6 Description of Test Software Setting ................................................................................ 9 1.7 Measurement Uncertainty .................................................................................................. 9 1.8 Test Facility ......................................................................................................................... 10 2. TEST SUMMARY ..................................................................................................................... 11 3. TEST SOFTWARE ................................................................................................................... 11 4. TEST EQUIPMENT AND TEST SITE ................................................................................... 12 5. CONDUCTED EMISSION ....................................................................................................... 14 5.1 Test Standard and Limit .................................................................................................... 14 5.2 Test Setup ........................................................................................................................... 14 5.3 Test Procedure ................................................................................................................... 14 5.4 Deviation From Test Standard ......................................................................................... 15 5.5 EUT Operating Mode ........................................................................................................ 15 5.6 Test Data ............................................................................................................................. 15 6. RADIATED EMISSION TEST ................................................................................................ 16 6.1 Test Standard and Limit .................................................................................................... 16 6.2 Test Setup ........................................................................................................................... 17 6.3 Test Procedure ................................................................................................................... 18 6.4 Deviation From Test Standard ......................................................................................... 19 6.5 EUT Operating Mode ........................................................................................................ 19 6.6 Test Data ............................................................................................................................. 19 7. BANDWIDTH ............................................................................................................................ 20 7.1 Test Standard and Limit .................................................................................................... 20 7.2 Test Setup ........................................................................................................................... 20 7.3 Test Procedure ................................................................................................................... 20 7.4 Deviation From Test Standard ......................................................................................... 20 7.5 EUT Operating Mode ........................................................................................................ 20 Report No.: TBR-C-202403-0223-21 Page: 3 of 33 TB-RF-074-1.0 7.6 Test Data ............................................................................................................................. 20 8. RELEASE TIME MEASUREMENT ....................................................................................... 21 8.1 Test Standard and Limit .................................................................................................... 21 8.2 Test Setup ...................................................…

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FCC ID:2AZI3F55 TB-RF-074-1.0 Appendix V EUT Test Photographs Photo of Setup for Radiated Emission (Below 1 GHz) Photo of Setup for Radiated Emission (Above 1 GHz) -----END OF REPORT-----