2ACP4BTO350wireless earbuds

Sentry Industries Limited Room A9, 7/F K11 Atelier, Victoria Dockside, 18 Salisbury Road, Tsim Sha Tsui, Hong Kong, China Office of Engineering Technology Federal Communications Commission 7435 Oakland Mills Road Columbia, MD 21046 USA Date: Apr. 15, 2026 Subject; Request for Confidentiality FCC ID: 2ACP4BTO350 To Whom It May Concern, Pursuant to the provisions of the Commission’s rules Title 47 Sections §0.457 and §0.459, we are requesting the Commission to withhold the following attachment(s) as confidential documents from public disclosure indefinitely. These documents contain detailed system and equipment descriptions and are considered as proprietary information in operation of the equipment. The public disclosure of these documents might be harmful to our company and would give competitors an unfair advantage in the market. Schematic Diagram Block Diagram Operational Description Parts List In additional to above mentioned documents, in order to comply with the marketing regulations in Title 47 CFR §2.803 and the importation rules in Title 47 CFR §2.1204, while ensuring that business sensitive information remains confidential until the actual marketing of newly authorized devices, we request Short Term Confidentiality of the following attachment(s); External Photos Test Setup Photos Internal Photos User Manual For 45 days, pursuant to Public Notice DA 04-1705. OR For 180 days pursuant to KDB 726920 D01. It is our understanding that all measurement test reports, FCC ID label format and correspondence during the certification review process cannot be granted as confidential documents and this information will be available for public review once the grant of equipment authorization is issued. Sincerely, Signature: Name: Peetu Melwani Title: Manager

Sentry Industries Limited Room A9, 7/F K11 Atelier, Victoria Dockside, 18 Salisbury Road, Tsim Sha Tsui, Hong Kong, China Apr. 15, 2026 Office of Engineering Technology Federal Communications Commission 7435 Oakland Mills Road Columbia, MD 21046 USA Subject: Explanation of differences between product types FCC ID: 2ACP4BTO350 Models: BTO350, BT500, BTDRONE To Whom It May Concern: We, The Sentry Industries Limited hereby declare that the model : BTO350 is identical with the model : BT500, BTDRONE, All models are the same circuit and RF module, except the model name Except for the different above, no other modification is performed. Sincerely, Sentry Industries Limited Signature: [Peetu Melwani, Manager]

Sentry Industries Limited Room A9, 7/F K11 Atelier, Victoria Dockside, 18 Salisbury Road, Tsim Sha Tsui, Hong Kong, China Letter of Authorization Company: Sentry Industries Limited Address: Room A9, 7/F K11 Atelier, Victoria Dockside, 18 Salisbury Road, Tsim Sha Tsui, Hong Kong, China Product Name: wireless earbuds Model Number(s): BTO350, BT500, BTDRONE Product Description: wireless earbuds We authorize MiCOM Labs Inc., 575 Boulder Court, Pleasanton, California 94566, USA, to act on our behalf on all matters concerning the certification of above named equipment. We declare that MiCOM Labs Inc. is allowed to forward all information related to the approval and certification of equipment to the regulatory agencies as required and to discuss any issues concerning the approval application. Any and all acts carried out by MiCOM Labs on our behalf shall have the same effect as acts of our own. Signature: Date: Apr. 15, 2026 Name: Peetu Melwani Title: Manager Company: Sentry Industries Limited

Report No.: AGC08189260303AP02 Page 1 of 3 EXTERNAL PHOTOS TOP VIEW OF EUT BOTTOM VIEW OF EUT Report No.: AGC08189260303AP02 Page 2 of 3 FRONT VIEW OF EUT BACK VIEW OF EUT Report No.: AGC08189260303AP02 Page 3 of 3 LEFT VIEW OF EUT RIGHT VIEW OF EUT ****************************************End of Report*************************************

FCC ID Label Location FCC ID: 2ACP4BTO350 30mm*30mm

Report No.: AGC08189260303AP02 Page 1 of 3 INTERNAL PHOTOS PORT VIEW OF EUT OPEN VIEW OF EUT Report No.: AGC08189260303AP02 Page 2 of 3 INTERNAL VIEW OF EUT (FIGURE 1) INTERNAL VIEW OF EUT (FIGURE 2) Report No.: AGC08189260303AP02 Page 3 of 3 INTERNAL VIEW OF EUT (FIGURE 3) BATTERY VIEW OF EUT ****************************************End of Report************************************* BT Antenna

Page 1 of 10 RF Exposure Report Report No.: AGC08189260303FH01 FCC ID : 2ACP4BTO350 APPLICATION PURPOSE : Original Equipment PRODUCT DESIGNATION : wireless earbuds BRAND NAME : SENTRY MODEL NAME : BTO350, BT500, BTDRONE APPLICANT : Sentry Industries Limited DATE OF ISSUE : Apr. 15, 2026 STANDARD(S) : FCC Part 2 Subpart J §2.1093 FCC KDB 447498 D01 V06 REPORT VERSION : V1.0 Attestation of Global Compliance (Shenzhen) Co., Ltd Report No.: AGC08189260303FH01 Page 2 of 10 Report Revise Record Report Version Revise Time Issued Date Valid Version Notes V1.0 / Apr. 15, 2026 Valid Initial Release Report No.: AGC08189260303FH01 Page 3 of 10 Table of Contents 1. General Information ........................................................................................................................................ 4 2. Product Information ........................................................................................................................................ 5 2.1 Product Technical Description ................................................................................................................... 5 3. Test Environment ............................................................................................................................................ 6 3.1 Address Of The Test Laboratory ............................................................................................................... 6 3.2 Test Facility ................................................................................................................................................ 6 3.3 Environmental Conditions ......................................................................................................................... 7 4. Portable Device Evaluation Method and Limit ............................................................................................. 8 5. Measurement Results ..................................................................................................................................... 9 6. Measurement Evaluation ................................................................................................................................ 9 Report No.: AGC08189260303FH01 Page 4 of 10 1. General Information Applicant Sentry Industries Limited Address Room A9, 7/F K11 Atelier, Victoria Dockside, 18 Salisbury Road, Tsim Sha Tsui, Hong Kong, China Manufacturer Shantou City Chaoyang District Xinhuasheng Electronics Factory Address Zhongshan Road, Hengshan Village, Gurao Town, Chaoyang District, Shantou City Factory Shantou City Chaoyang District Xinhuasheng Electronics Factory Address Zhongshan Road, Hengshan Village, Gurao Town, Chaoyang District, Shantou City Product Designation wireless earbuds Brand Name SENTRY Test Model BTO350 Series Model(s) BT500, BTDRONE Difference Description All models are the same circuit and RF module, except the model name Date of receipt of test item Mar. 20, 2026 Date of Test Mar. 20, 2026 to Apr. 15, 2026 Deviation from Standard No any deviation from the test method Condition of Test Sample Normal Test Result Pass Test Report Form No AGCER-FCC-RF Exposure-V1 Note: The test results of this report relate only to the tested sample identified in this report. Prepared By Thea Huang (Project Engineer) Apr. 15, 2026 Reviewed By Bibo Zhang (Reviewer) Apr. 15, 2026 Approved By Angela Li (Authorized Officer) Apr. 15, 2026 Report No.: AGC08189260303FH01 Page 5 of 10 2. Product Information 2.1 Product Technical Description Frequency Band (Operating) Bluetooth: 2.402GHz ~ 2.480GHz Other: Hardware Version HL-23-V1.1 Software Version S355 Modulation Type BR GFSK, EDR π /4-DQPSK, 8DPSK BLE GFSK 1Mbps GFSK 2Mbps Maximum Transmitter Power BR&EDR: 1.732dBm Device Category Portable (<20cm separation) Mobile (>20cm separation) Others: Antenna Diversity Single antenna Multiple antennas Tx diversity Rx diversity Tx/Rx diversity Antenna Designation PCB Antenna Antenna Gain -0.58dBi Minimum Assessment Distance 5mm Evaluation Applied MPE Evaluation SAR Evaluation Report No.: AGC08189260303FH01 Page 6 of 10 3. Test Environment 3.1 Address Of The Test Laboratory Laboratory: Attestation of Global Compliance (Shenzhen) Co., Ltd. Address: 101 & 201, Building 19(B5), Junfeng Industral Park, Chongqing Road, P.R.C. 3.2 Test Facility The test facility is recognized, certified, or accredited by the following organizations: CNAS-Lab Code: L5488 Attestation of Global Compliance (Shenzhen) Co., Ltd. has been assessed and proved to follow CNAS-CL01 Accreditation Criteria for Testing and Calibration Laboratories (identical to ISO/IEC17025: 2017 General Requirements for the Competence of Testing and Calibration Laboratories.) A2LA-Lab Cert. No.: 5054.02 Attestation of Global Compliance (Shenzhen) Co., Ltd. EMC Laboratory has been accredited by A2LA for technical competence in the field of electrical testing, and proved to follow ISO/IEC 17025: 2017 General Requirements for the Competence of Testing and Calibration Laboratories and any additional program requirements in the identified field of testing. FCC-Registration No.: 975832 Attestation of Global Compliance (Shenzhen) Co., Ltd. EMC Laboratory has been registered and fully described in a report filed with the FCC (Federal Communications Commission). The acceptance letter from the FCC is maintained in our files with Registration 975832. IC-Registration No.: 24842(CAB identifier: CN0063) Attestation of Global Compliance (Shenzhen) Co., Ltd. EMC Laboratory has been registered and fully described in a report filed with the Certification and Engineering Bureau of Industry Canada. The acceptance letter from the IC is maintained in our files with Registration 24842. Report No.: AGC08189260303FH01 Page 7 of 10 3.3 Environmental Conditions NORMAL CONDITIONS Temperature range (°C) 15 - 35 Relative humidity range 20 % - 75 % Pressure range (kPa) 86 - 106 Power supply DC 3.7V by battery or DC 5V by adapter Note: Th…

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Antennadescrib 1st Floor, Building 3, Keyuan Industrial Park, Xingguang Village, Huangjiang Town, Huangjiang Town, Dongguan City, Guangdong Province e AntennaplatePCBantenna ModelName2.4GANT CenterFrequency HorizontalVertical 2400 MHz 2450MHz2500MHz2400MHz2450MHz2500MHz - 1.26 -0.76-0.58-5.25-2.46-1.86 MAX.Gain-0.58dB PolarizationHorizontalandVertical AzimuthBeam Pattern Omni-directional Impedance50Ohm AntennaLength38.20mm manufacturer 制造商 地址 Shenzhen Shenhongsheng Circuit Board Co., Ltd. AntennaPhoto&Length(mm) Horizontal:2400MHz2450MHz2500MHz Power(dBm) Max:0Min:-40Scale:5/div Frequency (MHz) Gain(dB) MaxMinAvg 2400-1.26174-30.0801-7.18716 24500.765802-36.5604-7.48023 25000.585582-22.0315-6.59127 Vertical:2400MHz2450MHz2500MHz Power(dBm) Max:0Min:-30Scale:5/div Frequency (MHz) Gain(dB) MaxMinAvg 2400-5.2537-22.1424-12.4294 2450-2.4652-24.5837-10.4702 2500-1.86120-29.5214-9.20432

Page 1 of 66 FCC Test Report Report No.: AGC08189260303FR01 FCC ID : 2ACP4BTO350 APPLICATION PURPOSE : Original Equipment PRODUCT DESIGNATION : wireless earbuds BRAND NAME : SENTRY MODEL NAME : BTO350, BT500, BTDRONE APPLICANT : Sentry Industries Limited DATE OF ISSUE : Apr. 15, 2026 STANDARD(S) : FCC Part 15 Subpart C §15.247 REPORT VERSION : V1.0 Attestation of Global Compliance (Shenzhen) Co., Ltd Report No.: AGC08189260303FR01 Page 2 of 66 Report Revise Record Report Version Revise Time Issued Date Valid Version Notes V1.0 / Apr. 15, 2026 Valid Initial Release Report No.: AGC08189260303FR01 Page 3 of 66 Table of Contents 1. General Information ........................................................................................................................................ 5 2. Product Information ........................................................................................................................................ 6 2.1 Product Technical Description ................................................................................................................... 6 2.2 Test Frequency List ................................................................................................................................... 6 2.3 Related Submittal(S) / Grant (S) ............................................................................................................... 7 2.4 Test Methodology ...................................................................................................................................... 7 2.5 Receiver Input Bandwidth ......................................................................................................................... 7 2.6 Equally Average Use of Frequencies and Behaviour. ............................................................................. 7 2.7 Pseudorandom Frequency Hopping Sequence ........................................................................................ 8 2.8 Special Accessories .................................................................................................................................. 9 2.9 Equipment Modifications ........................................................................................................................... 9 2.10 Antenna Requirement ............................................................................................................................. 9 3. Test Environment .......................................................................................................................................... 10 3.1 Address of The Test Laboratory .............................................................................................................. 10 3.2 Test Facility .............................................................................................................................................. 10 3.3 Environmental Conditions ....................................................................................................................... 11 3.4 Measurement Uncertainty ....................................................................................................................... 11 3.5 List of Equipment Used ........................................................................................................................... 12 4. System Test Configuration ........................................................................................................................... 14 4.1 EUT Configuration ................................................................................................................................... 14 4.2 EUT Exercise ........................................................................................................................................... 14 4.3 Configuration of Tested System .............................................................................................................. 14 4.4 Equipment Used in Tested System ......................................................................................................... 15 4.5 Summary of Test Results ........................................................................................................................ 16 5. Description of Test Modes ........................................................................................................................... 17 6. RF Output Power Measurement .................................................................................................................. 18 6.1 Provisions Applicable .............................................................................................................................. 18 6.2 Measurement Procedure ......................................................................................................................... 18 6.3 Measurement Setup (Block Diagram of Configuration) .......................................................................... 18 6.4 Measurement Result ............................................................................................................................... 19 7. 20dB Bandwidth and 99% Occupied Bandwidth Measurement ............................................................... 23 7.1 Provisions Applicable .............................................................................................................................. 23 7.2 Measurement Procedure ......................................................................................................................... 23 7.3 Measurement Setup (Block Diagram of Configuration) .......................................................................... 23 7.4 Measurement Results ............................................................................................................................. 24 8. Conducted Band Edge and Out-of-Band Emissions ......................…

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Report No.: AGC08189260303AP01 Page 1 of 2 TEST SETUP PHOTOS RADIATED EMISSION TEST SETUP BELOW 1GHz RADIATED EMISSION TEST SETUP ABOVE 1GHz Report No.: AGC08189260303AP01 Page 2 of 2 AC POWER LINE CONDUCTED TEST SETUP RF CONDUCTED TEST SETUP ****************************************End of Report*************************************