FCC ID: 2AQK8-D91 Bluetooth headphone

handling instruction 1. Indicator light status 2. Voice prompt function (English voice) serial number operate indicate Voice event pronounce start (the machine or engine) The blue light is on for 1 second. start (the machine or engine) Pwron (pitch rising) 1.1 1.2 Standby (mobile phone not connected and TWS not connected) 1.3 Standby (TWS connected, not connected to mobile phone) The white light of the earphone indicator lights up for 2 seconds at the same time and goes out for 1 second. The white light of the main and auxiliary earphones lights up for 2 seconds and off for 1 second at the same time, and flashes circularly. 1.4 When the mobile phone is connected for standby. No flashing light 1.5 When pairing state The white light of the earphone indicator lights up for 2 seconds at the same time and goes out for 1 second. match connect Disconnect du dudu du Low electric prompt dududu one point six Pairing time 300 seconds switch an electrical device off Power Off (pitch drop) 1.7 1.8 1.9 When making a call Incoming call No flashing light No flashing light communicate by telephone No flashing light 1.10 listen to music No flashing light 1.11 1.12 1.13 1.14 switch an electrical device off The white light is on for 1 second. charge Fully charged White light is always on. Lights out. Alarm when the power is lower than 3.4V The white light flashes once every 5 seconds (the prompt tone is given once every 5 minutes). Turn on low latency Turn off low latency Gaming Mode Gaming Off Pairing Name: TS12 Pairing Password: 0000 1.15 Restore factory settings Blue and white lights flash three times at the same time. Power-saving mode: the headset will automatically turn off after 1.16 When the earphone is connected back to the mobile phone The blue light flashes once in 5S. 1.17 Restore factory settings Blue and white lights flash three times at the same time. Updated on September 9, 2023. 3. Button menu serial number function condition action Voice prompt connectionless 1. Headphones are turned on manually and automatically enter the pairing state;

2. The earphone automatically enters the pairing state after being taken out of the charging bin;

3. Automatically enter the Pairing state when disconnecting (prompt: pairing) Boot state Headphones automatically enter TWS teaming state when TWS and mobile phones are not connected. Update: 2023.09.09 Enter the pairing state Headphones TWS mutual matching Turn on the voice assistant Turn off voice assistant 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 start (the machine or engine) When it is turned off start (the machine or engine) When it is turned off Press and hold the power button for 4 seconds. The earphone is lifted from the seat. Standby/music state Standby/music state

"R" side, hit the power button three times.

"R" side, hit the power button three times. Open game mode Standby/music state Triple-click the power button on the "L" side. Turn off game mode Standby/music state Triple-click the power button on the "L" side. answer a phone call Incoming call Click the power button. Pwron (pitch rising) Pwron (pitch rising) du Prompt tone

(beep) Prompt tone

(beep) Gaming Mode Gaming Off 3.10 hang up the telephone 3.11 Refuse to listen to incoming calls When talking Click the power button. Incoming call Press and hold the power button for 1 second. 3.12 Play/pause Standby/music time Click the power button. 3.15 Last song When playing music Double-click the L key (note: it cannot be operated in standby mode) 3.16 Next song When playing music Double-click the R key (note: it cannot be operated in standby mode) 3.17 3.18 switch an electrical device off switch an electrical device off holding state Press and hold the power button for 4 seconds (TWS connection state turns off two headphones) Power Off At boot time Put the earphone into the cradle to charge (TWS connection state only turns off a single earphone) 3.19 Restore factory settings Under charging state Press and hold the power button for 8S, and the blue and white light flashes for 3 times; Restoring the factory settings only clears the phone pairing record, not the TWS pairing record. 3.20 Huilian mobile phone Connect back after starting up. 4.TWS function 4.1 onnected to mo When turned off/charged 5.DUT mode 5.1 Enter DUT mode Headphones are turned on -TWS reconnection-reconnection of mobile phones-pairing status (pairing status must exist with reconnection of mobile phones) After the two earphone buttons are turned on or lifted from the charging stand (the earphone is turned on), the TWS of the earphone is automatically connected successfully; The main earphone automatically enters the pairing mode (blue and red lights flash alternately), and the auxiliary earphone is in standby mode. Please go to the mobile phone to search for the headset pairing name, and click Connect;

Use the efficiency board to enter, or press the power-on key 5 times in the charging state (the flashing mode of DUT mode is that the earphone is blue and red, and it stays on for a long time). 5.2 Exit DUT mode state of charge Charge to exit DUT mode or exit automatically in 5 minutes. 6. Charging bin power and LED status 6.1 6.2 6.3 When charging the seat (plug in the 5V charging cable) is discharged (when the earpho The digital display of the charging bin shows the last digital jump (fully charged display is always on 100%). Headphone charging lights up with red light, and the charging bin displays the current power and the headset charging instruction (the left headset is charged, and the charging status bar on the left side of the charging bin flashes; The right earphone charges, and the charging status bar on the right side of the charging bin races); When the earphone is put into the charging bin, the battery display in the charging On-screen display at low battery. When the power is less than 10%, the power display flashes slowly for 10S when the earphone is put in. 6.4 Charging bin voltage 1. When there is no earphone in the charging bin, the voltage at the elastic needle of the charging bin is the battery voltage;

2. When the charging bin is put into the earphone for charging, the voltage at the pin of the charging bin is raised to 5V to charge the earphone;

3. After the earphone in the charging bin is fully charged, the voltage at the pin of the charging bin will drop from 5V to the battery voltage (the charging bin enters standby mode). FCC Warnning:

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 againstharmful interference in a residential installation. This equipment generates, uses and can radiateradio frequency energy and, if not installed and used in accordance with the instructions, maycause harmful interference to radio communications. However, there is no guarantee thatinterference will not occur in a particular installation. If this equipment does cause harmfulinterference to radio or television reception, which can be determined by turning the equipmentoff and on, the user is encouraged to try to correct the interference by one or more of thefollowing measures:

Reorient or relocate the receiving antenna. Increase the separation between the equipment and receiver. Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. Consult the dealer or an experienced radio/TV technician for help. Caution: Any changes or modications to this device not explicitly approved by manufacturer could void your authority to operate this equipment. 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 received, including interference that may cause undesired operation. interference, and (2) this device must accept any This equipment complies with FCC radiation exposure limits set forth for an uncontrolled environment. This equipment should be installed and operated with minimum distance 0cm between the radiator and your body.

Appendix ID Label Bluetooth headphone FCC ID: 2AQK8-D91 Model: D91 Size for the label: 20mm X 20mm Appendix ID Label Location FCC ID: 2AQK8-D91 TB-RF-074-1.0

CHANDASUNG TECH (SHENZHEN) CO., LTD Rm 802, Building B, Zhonghengsheng High-tech Zone, No.3 Xinyu Road Xinqiao Street, Baoan District, Shenzhen, China. Federal Communications Commission Authorization and Evaluation Division Equipment Authorization Branch 7435 Oakland Mills Road Columbia, MD 21046 2023-9-28 To whom it may concern:

We, CHANDASUNG TECH (SHENZHEN) CO., LTD, hereby certify that the equipment for which authorization is sought (FCC ID: 2AQK8-D91) is not covered equipment prohibited from receiving an equipment authorization pursuant to 2.903 of the FCC rules. We also certify that, as of the date of the filing of the application, we are not identified on the Covered List (https://www.fcc.gov/supplychain/coveredlist) as an entity producing covered equipment. By signing this form, we confirm the above and that we are aware of the application requirements listed under 2.911(b) and (d)(5) and (6). 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, 3 0 V

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_ 2 6 Signature Lisa Peng N/A CHANDASUNG TECH (SHENZHEN) CO., LTD

CHANDASUNG TECH (SHENZHEN) CO., LTD Add: Rm 802, Building B, Zhonghengsheng High-tech Zone, No.3 Xinyu Road Xinqiao Street, Baoan District, Shenzhen, China. Date: 2023-9-28 FCC ID: 2AQK8-D91 Dear Sir/Madam, We, CHANDASUNG TECH (SHENZHEN) CO., LTD Hereby declares the following statement for Federal Communications Commission, PCB board, circuit, structure and internal of these model(s) are the same, only difference is model name:

Product name: Bluetooth headphone Model no.: D91, TS12, HOLME Fit, M6, D99, D91A, D99, D99A, F15 Sincerely, Name/Title Company:

Address:

Phone:

Fax:

E-Mail:

Lisa Peng/N/A CHANDASUNG TECH (SHENZHEN) CO., LTD Rm 802, Building B, Zhonghengsheng High-tech Zone, No.3 Xinyu Road Xinqiao Street, Baoan District, Shenzhen, China.

+86-755-23597059

+86-755-23597058 lisa@chandasung.com

CONFIDENTIALITY REQUEST for Certification Service in USA Federal Communication Commission Equipment Authorization Division, Application Processing Branch 7435 Oakland Mills Road Columbia, MD 21046 Date:<2023-9-28>

Pursuant to Paragraphs 0.457 and 0.459 of the Commissions Rules (47 C.F.R.) and Section 552(b)(4) of the Freedom of Information Act, we requests confidentiality for the following products:

FCC ID 2AQK8-D91 Model name D91 For the product stated above, we request that the following information be held confidential;

Exhibits Long-Term Confidentiality Short-Term Confidentiality Short-Term Confidentiality Days External Photos Internal Photos Block Diagram Schematics Test Setup Photos Users Manual Parts List Tune Up Operational Descriptions The long-term confidentiality exhibits contain our trade secrets and proprietary information that could be of benefit to our competitors. The short-term confidentiality on the basis of ensuring that business sensitive information remains confidential until the actual marketing of our new device. If you have any questions, please feel free to contact me at the address shown below. Sincerely, Name/Title Lisa Peng/N/A Company:

Address:

CHANDASUNG TECH (SHENZHEN) CO., LTD Rm 802, Building B, Zhonghengsheng High-tech Zone, No.3 Xinyu Road Xinqiao Street, Baoan District, Shenzhen, China.

+86-755-23597059

+86-755-23597058 lisa@chandasung.com Phone:

Fax:

E-Mail:

CHANDASUNG TECH (SHENZHEN) CO., LTD Rm 802, Building B, Zhonghengsheng High-tech Zone, No.3 Xinyu Road Xinqiao Street, Baoan District, Shenzhen, China. Federal Communications Commission Authorization and Evaluation Division Equipment Authorization Branch 7435 Oakland Mills Road Columbia, MD 21046 2023-9-28 To whom it may concern:

We, the undersigned, hereby authorize Eurofins Product Service GmbH to act on our behalf in all matters relating to applications for equipment authorization FCC ID: 2AQK8-D91 including the signing of all documents related to these matters. Any and all acts carried out by Eurofins Product Service GmbH on our behalf shall have the same effect as acts of our own. By signing this application form, we agree to Eurofins current valid General Terms and Conditions

(AGB),Testing and Certification Regulations (PZO) which can be viewed on following website www.eurofins.de/ee or retrieved on request. We also hereby certify that no party to this application is subject to a denial of benefits, including FCC benefits, pursuant to Section 5301 of the Anti-Drug Abuse Act of 1988, 21 U.S.C. 862. Sincerely, Name/Title Company:

Address:

Phone:

Fax:

E-Mail:

Lisa Peng/N/A CHANDASUNG TECH (SHENZHEN) CO., LTD Rm 802, Building B, Zhonghengsheng High-tech Zone, No.3 Xinyu Road Xinqiao Street, Baoan District, Shenzhen, China.

+86-755-23597059

+86-755-23597058 lisa@chandasung.com

2.91 1(d}(7)-U, V05 48 {model] US_Agent_ CHANDASUNG TECH (SHENZHEN) CO., LTD Rm 802, Building B, Zhonghengsheng High-tech Zone, No.3 Xinyu Road Xingiao Street, Baoan District, Shenzhen, China. Federal Communications Commission Authorization and Evaluation Division Equipment Authorization Branch 7435 Oakland Mills Road Columbia, MD 21046 2023-53-28 U.S. Agent Designation CHANDASUNG TECH (SHENZHEN) CO., LTD acknowledges their consent for the following contact located in the United Siaies io aci as their agent for service of process for the equipiierit for which autharizZation is sougit (FCC iD: 2AQK8-D91)-

Name and company of U.S. agent: ACT Lab LLC Physical U.S. address of agent: 3280 East 59th Street Long Beach, CA 90805 United States FRN of U.S. agent: 0033465568 Email address of U.S. agent: shuber@act-lab.com ACT Lab LLC acknowledges their obligation to accept service of process on behalf of CHANDASUNG TECH

(SHENZHEN) CO., LTD. CHANDASUNG TECH (SHENZHEN) CO., LTD with the FRN [0027685387] accepts its obligation to maintain an agent for service of process in the United States for no less than one 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 Gommission-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 ieiter is basd on the referenced rule paris of Tile 47 of the CFR as weil as KDB 986446 DO1. An expiration date for this letter does not exist. In case the US. agent changes, the grantee is obligated to notify the FCC within 30 days via the granting TCB. Sincerely, BN Signature Signature Lisa Peng Scott Huber N/A Senior Technical Director CHANDASUNG TECH (SHENZHEN) CO., LTD ACT Lab LLC