2A4WD-ZK-1002TBluetooth Audio Power Amplifier

Qingdao Wuzhi Intelligent Technology Co., Ltd. Federal Communications Commission Authorization and Evaluation Division Equipment Authorization Branch 7435 Oakland Mills Road Columbia, MD 21046 [January 4, 2026] U.S. Agent Designation [Qingdao Wuzhi Intelligent Technology Co., Ltd.] acknowledges their consent for the following contact located in the United States to act as their agent for service of process for the equipment for which authorization is sought FCC ID: 2A4WD-ZK-1002T Name and company of U.S. agent: [GLOCERTS TECHNOLOGY INC] Physical U.S. address of agent: [19784 SUNKISSED RIDGE DR, RIVERSIDE, CA 92507] FRN of U.S. agent: [0036339737] Email address of U.S. agent: [[email protected]] Telephone of U.S.agent: (626) 588-8039 [GLOCERTS TECHNOLOGY INC] acknowledges their obligation to accept service of process on behalf of [Qingdao Wuzhi Intelligent Technology Co., Ltd.]. [Qingdao Wuzhi Intelligent Technology Co., Ltd.] with the FRN [0032008856] accepts its obligation to maintain an agent for service of process in the United States for no less than 1 year after either the grantee has permanently terminated all marketing and importation of the applicable equipment within the U.S., or the conclusion of any Commission-related administrative or judicial proceeding involving the equipment, whichever is later. By signing this form, we confirm the above and that we are aware of the application requirements listed under § 2.911(d)(7). The information provided in this letter is based on the referenced rule parts of Title 47 of the CFR as well as KDB 986446 D01. Sincerely, Signature Signature [CHENCHEN ZHANG] [Huiying Fan] [General manager] [Director] [Qingdao Wuzhi Intelligent Technology Co., Ltd.] [GLOCERTS TECHNOLOGY INC]

Qingdao Wuzhi Intelligent Technology Co., Ltd. (January 4, 2026) Eurofins Electrical and Electronic Testing NA, Inc. 914 West Patapsco Avenue Baltimore, MD 21230 RE: Attestation Statements Part 2.911(d)(5)(i) request for FCC ID:2A4WD-ZK-1002T [Qingdao Wuzhi Intelligent 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. We also certify that, as of the date of the filing of the application, the equipment does not utilize cyber-security or anti-virus software from Kaspersky Lab, Inc, or any of its successors and assignees, which is also on the “covered list”. Sincerely, (Applicant signature) (Applicant printed name)CHENCHEN ZHANG Qingdao Wuzhi Intelligent Technology Co., Ltd. (January 4, 2026) Eurofins Electrical and Electronic Testing NA, Inc. 914 West Patapsco Avenue Baltimore, MD 21230 RE: Attestation Statements Part 2.911(d)(5)(ii) request for FCC ID:2A4WD-ZK-1002T [Qingdao Wuzhi Intelligent 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 an entity producing “covered” equipment. Sincerely, (Applicant signature) (Applicant printed name)CHENCHEN ZHANG

Qingdao Wuzhi Intelligent Technology Co., Ltd. Model Difference Data:January 4, 2026 Product description: Bluetooth Audio Power Amplifier Model name: ZK-502T, ZK-1002T, ZK-1001U, ZK-1602T, ZK-AS21, ZK-TB21Q Trade Name: WUZHI AUDIO FCC ID: 2A4WD-ZK-1002T All the model are the same circuit and RF module, only the model names are different. Regards Sincerely Client’s signature : Client’s name / title : CHENCHEN ZHANG(General manager) Contact information / address:No. 438, Xiaoxinhe Road, Huangdao District, Qingdao City, Shandong Province, China

Qingdao Wuzhi Intelligent Technology Co., Ltd. (January 4, 2026) Eurofins Electrical and Electronic Testing NA, Inc. 914 West Patapsco Avenue Baltimore, MD 21230 RE: CONFIDENTIALITY REQUEST FOR (Bluetooth Audio Power Amplifier / ZK- 502T, ZK-1002T, ZK-1001U, ZK-1602T, ZK-AS21, ZK-TB21Q / FCC ID: 2A4WD- ZK-1002T ) To Whom It May Concern: This letter serves as an official request for confidentiality under sections 0.457 and 0.459 of CFR 47. We have requested that the Exhibits Long-Term Confidentiality Short-Term Confidentiality NOTE 2 ID Label/Location No No Attestation Statement No No External Photos No ☐ Block Diagram ☒ ☐ Schematics ☒ ☐ Test Report No No Test Setup Photos No ☐ User’s Manual ☐ NOTE 1 ☒ Internal Photos ☐ NOTE 1 ☒ Parts List / Tune Up ☐ ☐ RF Exposure Info No No Operational Description ☒ ☐ Cover Letter(s) No No SDR Software / Security Info ☐ No required to be submitted with this application be permanently withheld from public review. Above mentioned document contains detailed system and equipment description are considered as proprietary information in operation of the equipment. The public disclosure of above documents might be harmful to our company and would give competitor an unfair advantage in the market. Please contact me if there is any information you may need. Sincerely, Signature: Name: CHENCHEN ZHANG Title: General manager

Qingdao Wuzhi Intelligent Technology Co., Ltd. (January 4, 2026) Eurofins Electrical and Electronic Testing NA, Inc. 914 West Patapsco Avenue Baltimore, MD 21230 RE: LETTER OF AGENT AUTHORIZATION To Whom It May Concern: We, the undersigned, hereby authorize (Shenzhen CTB Testing Technology Co., Ltd.) to act on our behalf in all matters relating to application for equipment authorization, including the signing of all documents relating to these matters. We also hereby certify that no party to the application authorized hereunder is subject to the denial of benefits, including FCC benefits, pursuant to Section 5301 of the Anti-Drug Abuse Act of 1988, 21 U.S.C.853(a). This agreement expires one year from the current date. Sincerely, Signature: Name: CHENCHEN ZHANG Title: General manager

Shenzhen CTB Testing Technology Co., Ltd. Report Tel: 4008-707-283 Web: http://www.ctb-lab.net Page 1 of 3 Model: ZK-502T External Photos Shenzhen CTB Testing Technology Co., Ltd. Report Tel: 4008-707-283 Web: http://www.ctb-lab.net Page 2 of 3 Shenzhen CTB Testing Technology Co., Ltd. Report Tel: 4008-707-283 Web: http://www.ctb-lab.net Page 3 of 3

FCC ID LABEL: Label Location: FCC ID: 2A4WD-ZK-1002T Model No.: ZK-502T

FCC §15.247 (i), §2.1091 – RF Exposure FCC ID: 2A4WD-ZK-1002T Applied procedures / limit According to FCC §15.247(i) and §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 Occupational / Controlled Exposure Frequency Range (MHz) Electric Field Strength (E) (V/m) Magnetic Field Strength (H) (A/m) Power Density (S) (mW/ cm 2 ) Averaging Time |E| 2 ,|H| 2 or S (minutes) 0.3-3.0 614 1.63 (100)* 6 3.0-30 1842 / f 4.89 / f (900 / f)* 6 30-300 61.4 0.163 1.0 6 300-1500 F/300 6 1500-100,000 5 6 Note: ƒ is frequency in MHz * = Power density limit is applicable at frequencies greater than 100 MHz Limits for General Population / Uncontrolled Exposure Frequency Range (MHz) Electric Field Strength (E) (V/m) Magnetic Field Strength (H) (A/m) Power Density (S) (mW/ cm 2 ) Averaging Time |E| 2 ,|H| 2 or S (minutes) 0.3-1.34 614 1.63 (100)* 30 1.34-30 824/f 2.19/f (180/f)* 30 30-300 27.5 0.073 0.2 30 300-1500 F/1500 30 1500-100,000 1.0 30 Note: f = frequency in MHz * = Plane-wave equivalent power density MPE PREDICTION Predication of MPE limit at a given distance, Equation from OET Bulletin 65, Edition 97-01 Where: S = power density P = power input to 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,R=20cm Test Result of RF Exposure Evaluation Modes& Channel Freq. (MHz) Tune up Produce power Maximu m peak output power (dBm) Output power to antenna (mW) Antenna Gain (numeric) Power Density (S) (mW/ cm2) Limit (mW / cm2 ) Result EDR 8DPSK &2441 -3±1 -2 0.6310 1.5488 (1.9dBi) 0.00019 1 Pass

V . S .W . R < 1.4 Polarization Type V ertical & Horizontal Frequenc Range 2400 ~ 2500GHz Input Impendence(ohm) 50 Efficiency (dB) 6 0.2 % 6 0.2 %-3.61.91.2 Maximum Power (dBm)1.7 (XY-plane) Gain (dBi)1.2 (Avg Gain XY-plane) Peak EIRP(dBm)1.2 Tot. Rad. Pwr. (dBm)-1.2 (Input pwr – loss pwr) Product specification Quick Reference Date Antenna module on the system board Ant. Port Input Pwr. (dBm)0 (Typ. BT class 2 output power) Directivity (dBi)1 (all direction antenna) Minimum Power (dBm)-4(XY-plane) Avg. Power (dBm)-0.5(XY-plane) All the technical data and information contained herein are subject to change without prior notice Antenna Layout & module on the system board Antenna Gain Gain Table Unit in dBi @2.44GHzXY-planeXZ-planeYZ-plane Efficiency Peak Avg. Peak Avg. Peak Avg. Module Board -0.51.1-3.0 Return Loss The Environment of Antenna Radiation Pattern 3D radiation pattern diagram XY-planeXZ-planeYZ-plane

Report Tel: 4008-707-283 Web: http://www.ctb-lab.net Page 1 of 56 TEST REPORT Compiled by: Reviewed by: Approved by: Kai Chen Martin Feng Bin Mei / Director Note: If there is any objection to the inspection results in this report, please submit a written report to the company within 15 days from the date of receiving the report. The test report is effective only with both signature and specialized stamp. This result(s) shown in this report refer only to the sample(s) tested. Without written approval of Shenzhen CTB Testing Technology Co., Ltd. this report can’t be reproduced except in full. The tested sample(s) and the sample information are provided by the client. “*” indicates the testing items were fulfilled by subcontracted lab. “#” indicates the items are not in CNAS accreditation scope. Test item description: Bluetooth Audio Power Amplifier FCC ID: 2A4WD-ZK-1002T Trademark(s): WUZHI AUDIO Model/Type reference: ZK-502T, ZK-1002T, ZK-1001U, ZK-1602T, ZK-AS21, ZK-TB21Q Applicant’s name: Qingdao Wuzhi Intelligent Technology Co., Ltd. Address: No. 438, Xiaoxinhe Road, Huangdao District, Qingdao City, Shandong Province, China Manufacturer: Qingdao Wuzhi Intelligent Technology Co., Ltd. Address: No. 438, Xiaoxinhe Road, Huangdao District, Qingdao City, Shandong Province, China Prepared By: Shenzhen CTB Testing Technology Co., Ltd. Address: 1&2/F., Building A, No.26, Xinhe Road, Xinqiao, Xinqiao Street, Bao'an District, Shenzhen, Guangdong, China Sample Received Date: Dec. 12, 2025 Sample tested Date: Dec. 12, 2025 to Dec. 25, 2025 Issue Date: Dec. 25, 2025 Report No.: CTB25121201001RF01 Test Standards FCC CFR Title 47 Part 15 Subpart C Section 15.247 ANSI C63.10:2020 Test Results PASS Remark: This is Bluetooth radio test report. Shenzhen CTB Testing Technology Co., Ltd. Report No.:CTB25121201001RF01 Report Tel: 4008-707-283 Web: http://www.ctb-lab.net Page 2 of 56 TABLE OF CONTENT Test Report Declaration Page 1. VERSION .......................................................................... 4 2. TEST SUMMARY ................................................................... 5 3. MEASUREMENT UNCERTAINTY ..................................................... 6 4. PRODUCT INFORMATION AND TEST SETUP .......................................... 7 4.1 Product Information .................................................................... 7 4.2 Test Setup Configuration ............................................................... 7 4.3 Support Equipment .................................................................... 7 4.4 Channel List .......................................................................... 8 4.5 Test Mode ............................................................................ 8 4.6 Test Environment ...................................................................... 8 5. TEST FACILITY AND TEST INSTRUMENT USED ....................................... 9 5.1 Test Facility ........................................................................... 9 5.2 Test Instrument Used .................................................................. 9 6. AC POWER LINE CONDUCTED EMISSION ............................................ 12 6.1 Block Diagram Of Test Setup .......................................................... 12 6.2 Limit ................................................................................ 12 6.3 Test procedure ....................................................................... 12 6.4 Test Result .......................................................................... 14 7. RADIATED SPURIOUS EMISSION ................................................... 16 7.1 Block Diagram Of Test Setup .......................................................... 16 7.2 Limit ................................................................................ 16 7.3 Test procedure ....................................................................... 17 7.4 Test Result .......................................................................... 18 8. BAND EDGE AND RF COUNDUCTED SPURIOUS EMISSIONS .......................... 27 8.1 Block Diagram Of Test Setup .......................................................... 27 8.2 Limit ................................................................................ 27 8.3 Test procedure ....................................................................... 27 8.4 Test Result .......................................................................... 28 9. COUDUCTED PEAK OUTPUT POWER ............................................... 35 9.1 Block Diagram Of Test Setup .......................................................... 35 9.2 Limit ................................................................................ 35 9.3 Test procedure ....................................................................... 35 9.4 Test Result .......................................................................... 35 10. 20DB OCCUPIED BANDWIDTH...................................................... 39 10.1 Block Diagram Of Test Setup ......................................................... 39 10.2 Limit ............................................................................... 39 10.3 Test procedure ...................................................................... 39 10.4 Test Result ......................................................................... 39 11. CARRIER FREQUENCIES SEPARATION ............................................. 43 11.1 Block Diagram Of Test Setup ......................................................... 43 11.2 Limit ............................................................................... 43 11.3 Test procedure ...................................................................... 43 11.4 Test Result ......................................................................... 43 12. HOPPING CHANNEL NUMBER ...................................................... 47 12.1 Block Diagram Of Test Setup ......…

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Shenzhen CTB Testing Technology Co., Ltd. Report Tel: 4008-707-283 Web: http://www.ctb-lab.net Page 1 of 2 Model: ZK-502T Radiated Emission Below 1G Above 1G Shenzhen CTB Testing Technology Co., Ltd. Report Tel: 4008-707-283 Web: http://www.ctb-lab.net Page 2 of 2 Conducted emissions