2ALHZBT-1700Bluetooth headphones

KO-STAR DEVELOPMENT CO.,LTD Feb.25, 2021 Office of Engineering Technology Federal Communications Commission 7435 Oakland Mills Road Columbia, MD 21046 USA Subject: Explanation of differences between product types FCC ID : 2ALHZBT-1700 Model Number: MZX5500, MZX5500-BLK, MZX5500-CGRY, MZX5500- MT, MZX5500-ICY, BT-1090B, BT-1090, BT-2020, BT-1100B, BT- 1100BF, BT-1100, BT-1300, BT-1300B, BT-1300BF, BT-686, BT-102, BT-685, BT-1102, BT-1103, BT-937, BT-739, BT-1108, BT-1106, BT-936, BT-1060F, BT-1060, BT-1092, BT-1094, BT-1080, BT-229, BT-1104, BT- 1500, BT-1600, BT-1700, BT-1800, BT-1066, BT-1070, BT-688, BT-689, BT-222, BT-222F, BT-1050, BT-2030, BT261, BT-1501, BT-601, BT- 1069, BT-1106, BT-1093, BT-235 To Whom It May Concern: We, The KO-STAR DEVELOPMENT CO., LTD hereby declare that the models are identical except the model name and color. Except for the different above, no other modification is performed. Sincerely, Signature: KO-STAR DEVELOPMENT CO., LTD Contact person: LING YAN

KO-STAR DEVELOPMENT CO., LTD Agent Authorization Company: KO-STAR DEVELOPMENT CO., LTD Address: No.3, Yicun Industrial Area, Xikeng, Henggang Town, Longgang District Shenzhen, China Product Name: Bluetooth headphones Model Number(s): MZX5500, MZX5500-BLK, MZX5500-CGRY, MZX5500-MT, MZX5500-ICY, BT-1090B, BT-1090, BT-2020, BT-1100B, BT-1100BF, BT-1100, BT- 1300, BT-1300B, BT-1300BF, BT-686, BT-102, BT-685, BT-1102, BT-1103, BT-937, BT-739, BT-1108, BT-1106, BT-936, BT-1060F, BT-1060, BT-1092, BT-1094, BT- 1080, BT-229, BT-1104, BT-1500, BT-1600, BT-1700, BT-1800, BT-1066, BT-1070, BT-688, BT-689, BT-222, BT-222F, BT-1050, BT-2030, BT261, BT-1501, BT-601, BT-1069, BT-1106, BT-1093, BT-235 Product Description: Bluetooth headphones 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: 2021-04-25 Name: LING YAN Company: KO-STAR DEVELOPMENT CO., LTD

KO-STAR DEVELOPMENT CO.,LTD Office of Engineering Technology Federal Communications Commission 7435 Oakland Mills Road Columbia, MD 21046 USA Date: 2021-01-25 Subject; Request for Confidentiality FCC ID: 2ALHZBT-1700 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 Parts List Operational Description Tune-up Procedure 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 KO-STAR DEVELOPMENT CO., LTD Contact person: LING YAN

External Photos WHOLE VIEW OF EUT TOP VIEW OF EUT BOTTOM VIEW OF EUT FRONT VIEW OF EUT BACK VIEW OF EUT LEFT VIEW OF EUT RIGHT VIEW OF EUT VIEW OF EUT(PORT)-1 VIEW OF EUT(PORT)-2

FCC ID Label Location 5mm&15mm FCC ID: 2ALHZBT-1700

Internal Photos OPEN VIEW OF EUT VIEW OF BATTERY INTERNAL VIEW OF EUT-1 INTERNAL VIEW OF EUT-2 INTERNAL VIEW OF EUT-3 INTERNAL VIEW OF EUT-4 BT Antenna INTERNAL VIEW OF EUT-5 INTERNAL VIEW OF EUT-6

RF EXPOSURE EVALUATION 1. PRODUCT INFORMATION Product Description Bluetooth headphones Model Name MZX5500, MZX5500-BLK, MZX5500-CGRY, MZX5500-MT, MZX5500-ICY, BT-1090B, BT-1090, BT-2020, BT-1100B, BT-1100BF, BT-1100, BT-1300, BT-1300B, BT-1300BF, BT-686, BT-102, BT-685, BT-1102, BT-1103, BT-937, BT-739, BT-1108, BT-1106, BT-936, BT-1060F, BT-1060, BT-1092, BT-1094, BT-1080, BT-229, BT-1104, BT-1500, BT-1600, BT-1700, BT-1800, BT-1066, BT-1070, BT-688, BT-689, BT-222, BT-222F, BT-1050, BT-2030, BT261, BT-1501, BT-601, BT-1069, BT-1106, BT-1093, BT-235 FCC ID 2ALHZBT-1700 2. EVALUATION METHOD According to 447498 D01 General RF Exposure Guidance v06 The 1-g and 10-g SAR test exclusion thresholds for 100 MHz to 6 GHz at test separation distances ≤ 50 mm are determined by: [(max. power of channel, including tune-up tolerance, mW)/(min. test separation distance, mm)] ·[√f(GHz)] ≤ 3.0 for 1-g SAR and ≤ 7.5 for 10-g extremity SAR. Where f(GHz) is the RF channel transmit frequency in GHz Power and distance are rounded to the nearest mW and mm before calculation 3. CALCULATION BR/EDR: P t = -2.589dBm=0.55mW The value of the Maximum output power P t is referred to the test report of the CFR47 §15.247. The result for RF exposure evaluation SAR=(0.55mW /5mm) .[√2.480GHz)]=0.17<3.0 for 1-g SAR and ≤ 7.5 for 10-g extremity SAR. 4. CONCLUSION The SAR evaluation is not required.

Page 1 of 67 FCC Test Report Report No.: AGC05177201206FE03 FCC ID : 2ALHZBT-1700 APPLICATION PURPOSE : Original Equipment PRODUCT DESIGNATION : Bluetooth headphones BRAND NAME : N/A MODEL NAME : MZX5500, MZX5500-BLK, MZX5500-CGRY, MZX5500-MT, MZX5500-ICY, BT-1090B, BT-1090, BT-2020, BT-1100B, BT-1100BF, BT-1100, BT-1300, BT-1300B, BT-1300BF, BT-686, BT-102, BT-685, BT-1102, BT-1103, BT-937, BT-739, BT-1108, BT-1106, BT-936, BT-1060F, BT-1060, BT-1092, BT-1094, BT-1080, BT-229, BT-1104, BT-1500, BT-1600, BT-1700, BT-1800, BT-1066, BT-1070, BT-688, BT-689, BT-222, BT-222F, BT-1050, BT-2030, BT261, BT-1501, BT-601, BT-1069, BT-1106, BT-1093, BT-235 APPLICANT : KO-STAR DEVELOPMENT CO.,LTD DATE OF ISSUE : Jan. 25, 2021 STANDARD(S) : FCC Part 15.247 REPORT VERSION : V1.0 Attestation of Global Compliance (Shenzhen) Co., Ltd Report No.: AGC05177201206FE03 Page 2 of 67 REPORT REVISE RECORD Report Version Revise Time Issued Date Valid Version Notes V1.0 / Jan. 25, 2021 Valid Initial Release Report No.: AGC05177201206FE03 Page 3 of 67 TABLE OF CONTENTS 1. VERIFICATION OF CONFORMITY ............................................................................................................... 5 2. GENERAL INFORMATION ............................................................................................................................ 6 2.1. PRODUCT DESCRIPTION ..................................................................................................................... 6 2.2. TABLE OF CARRIER FREQUENCYS ..................................................................................................... 6 2.3. RECEIVER INPUT BANDWIDTH ............................................................................................................ 7 2.4. EXAMPLE OF A HOPPING SEQUENCY IN DATA MODE ....................................................................... 7 2.5. EQUALLY AVERAGE USE OF FREQUENCIES AND BEHAVIOUR ........................................................ 7 2.6. RELATED SUBMITTAL(S) / GRANT (S) .................................................................................................. 8 2.7. TEST METHODOLOGY .......................................................................................................................... 8 2.8. SPECIAL ACCESSORIES ....................................................................................................................... 8 2.9. EQUIPMENT MODIFICATIONS .............................................................................................................. 8 2.10. ANTENNA REQUIREMENT .................................................................................................................. 8 3. MEASUREMENT UNCERTAINTY ................................................................................................................. 9 4. DESCRIPTION OF TEST MODES ............................................................................................................... 10 5. SYSTEM TEST CONFIGURATION ............................................................................................................. 11 5.1. CONFIGURATION OF EUT SYSTEM .................................................................................................... 11 5.2. EQUIPMENT USED IN TESTED SYSTEM ............................................................................................. 11 5.3. SUMMARY OF TEST RESULTS ............................................................................................................. 11 6. TEST FACILITY ........................................................................................................................................... 12 7. PEAK OUTPUT POWER ............................................................................................................................. 13 7.1. MEASUREMENT PROCEDURE ........................................................................................................... 13 7.2. TEST SET-UP (BLOCK DIAGRAM OF CONFIGURATION) ................................................................... 13 7.3. LIMITS AND MEASUREMENT RESULT ............................................................................................... 14 8. 20DB BANDWIDTH ..................................................................................................................................... 18 8.1. MEASUREMENT PROCEDURE ........................................................................................................... 18 8.2. TEST SET-UP (BLOCK DIAGRAM OF CONFIGURATION) ................................................................... 18 8.3. LIMITS AND MEASUREMENT RESULTS ............................................................................................. 19 9. CONDUCTED SPURIOUS EMISSION ........................................................................................................ 23 9.1. MEASUREMENT PROCEDURE ........................................................................................................... 23 Report No.: AGC05177201206FE03 Page 4 of 67 9.2. TEST SET-UP (BLOCK DIAGRAM OF CONFIGURATION) ................................................................... 23 9.3. MEASUREMENT EQUIPMENT USED .................................................................................................. 23 9.4. LIMITS AND MEASUREMENT RESULT ............................................................................................... 23 10. RADIATED EMISSION ............................................................................................................................... 34 10.1. MEASUREMENT PROCEDURE ......................................................................................................... 34 10.2. TEST SETUP ....................................................................................................................................... 36 10.3. LIMITS AND MEASUR…

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Report No.: AGC05177201206FE03 Page 57 of 67 APPENDIX A: PHOTOGRAPHS OF TEST SETUP RADIATED EMISSION TEST SETUP BELOW 1GHz RADIATED EMISSION TEST SETUP ABOVE 1GHz Report No.: AGC05177201206FE03 Page 58 of 67 CONDUCTED EMISSION TEST SETUP CONDUCTED TEST SETUP Report No.: AGC05177201206FE03 Page 59 of 67 APPENDIX B: PHOTOGRAPHS OF EUT WHOLE VIEW OF EUT TOP VIEW OF EUT Report No.: AGC05177201206FE03 Page 60 of 67 BOTTOM VIEW OF EUT FRONT VIEW OF EUT Report No.: AGC05177201206FE03 Page 61 of 67 BACK VIEW OF EUT LEFT VIEW OF EUT Report No.: AGC05177201206FE03 Page 62 of 67 RIGHT VIEW OF EUT VIEW OF EUT(PORT)-1 Report No.: AGC05177201206FE03 Page 63 of 67 VIEW OF EUT(PORT)-2 OPEN VIEW OF EUT Report No.: AGC05177201206FE03 Page 64 of 67 VIEW OF BATTERY INTERNAL VIEW OF EUT-1 Report No.: AGC05177201206FE03 Page 65 of 67 INTERNAL VIEW OF EUT-2 INTERNAL VIEW OF EUT-3 Report No.: AGC05177201206FE03 Page 66 of 67 INTERNAL VIEW OF EUT-4 INTERNAL VIEW OF EUT-5 BT Antenna Report No.: AGC05177201206FE03 Page 67 of 67 INTERNAL VIEW OF EUT-6 ----END OF REPORT---- Conditions of Issuance of Test Reports 1. All samples and goods are accepted by the Attestation of Global Compliance (Shenzhen) Co., Ltd (the “Company”) solely for testing and reporting in accordance with the following terms and conditions. The company provides its services on the basis that such terms and conditions constitute express agreement between the company and any person, firm or company requesting its services (the “Clients”). 2. Any report issued by Company as a result of this application for testing services (the “Report”) shall be issued in confidence to the Clients and the Report will be strictly treated as such by the Company. It may not be reproduced either in its entirety or in part and it may not be used for advertising or other unauthorized purposes without the written consent of the Company. The Clients to whom the Report is issued may, however, show or send it, or a certified copy thereof prepared by the Company to its customer, supplier or other persons directly concerned. The Company will not, without the consent of the Clients, enter into any discussion or correspondence with any third party concerning the contents of the Report, unless required by the relevant governmental authorities, laws or court orders. 3.The Company shall not be called or be liable to be called to give evidence or testimony on the Report in a court of law without its prior written consent, unless required by the relevant governmental authorities, laws or court orders. 4. The non-CMA report issued by AGC is only permitted to be used by the client as internal reference use and shall not be used for public demonstration purpose. 5. In the event of the improper use of the report as determined by the Company, the Company reserves the right to withdraw it, and to adopt any other additional remedies which may be appropriate. 6. Samples submitted for testing are accepted on the understanding that the Report issued cannot form the basis of, or be the instrument for, any legal action against the Company. 7. The Company will not be liable for or accept responsibility for any loss or damage however arising from the use of information contained in any of its Reports or in any communication whatsoever about its said tests or investigations. 8.Clients wishing to use the Report in court proceedings or arbitration shall inform the Company to that effect prior to submitting the sample for testing. 9. The Company is not responsible for recalling the electronic version of the original report when any revision is made to them. The Client assumes the responsibility to providing the revised version to any interested party who uses them. 10. Subject to the variable length of retention time for test data and report stored hereinto as otherwise specifically required by individual accreditation authorities, the Company will only keep the supporting test data and information of the test report for a period of six years. The data and information will be disposed of after the aforementioned retention period has elapsed. Under no circumstances shall we provide any data and information which has been disposed of after retention period. Under no circumstances shall we be liable for damage of any kind, including (but not limited to) compensatory damages, lost profits, lost data, or any form of special, incidental, indirect, consequential or punitive damages of any kind, whether based on breach of contract of warranty, tort (including negligence), product liability or otherwise, even if we are informed in advance of the possibility of such damages.

Test Setup Photos RADIATED EMISSION TEST SETUP BELOW 1GHz RADIATED EMISSION TEST SETUP ABOVE 1GHz CONDUCTED EMISSION TEST SETUP CONDUCTED TEST SETUP