Langsdom Opetec Race 4 Directional Sound Headphones


We appreciate you for purchasing the Langsdom Opetec Race 4 Bone Conduction Headphone, the following instructions will guide you to use it easily.


Hang the headphone on the outer ear, align the sound holAes with the ear canal and adjust to the wearing comfort angle.







  1. Sound hole
  2. Multifunction button
  3. Microphone
  4. Indicator light
  5. Volume up
  6. Volume down
  7. Charging port

Volume up:

  • Volume up x2
  • Previous song x3

Volume down:

  • Volume down x2
  • Next song x3

Multifunction button:

  • Play/Pause/Answer/ Hang up xl
  • Long press about 2s: Reject

Tip: During a call, press twice the multifunction button to hang up the current one and answer the incoming one.

Manually On/Off

  1. When the headphone is off, long press the multifunction button about 2 seconds to power on.
  2. When the headphone is on, long press the multifunction button about 3 seconds to power off.



How to pair
When the Bluetooth is paired for the first time, long press the multifunction button about 2 seconds, the headphone will automatically turn on the Bluetooth function after the blue light is on for about 1 second and the red and blue lights flash alternately. Then search for Bluetooth devices, select the “Opetec Race 4 to pair and to be successful if the blue light flashes once every 5 seconds.

Extended Link

  1. Disconnect the headphone from device A after it Connected;
  2. Turn on the Bluetooth of device B, search for Opetec Race 4 and select to connect;
  3. Turn on the Bluetooth of device A and select Opetec Race 4 to connect.

Automatic Pairing

  1. After power on, the headphone will automatically connect back to the last Bluetooth device within about 10 minutes, otherwise power off automatically;
  2. When being disconnected from the device beyond the effective distance, the headphone will automatically reconnect after returning to the effective distance within 10 minutes;
  3. When the headphone automatically turn on the Bluetooth function after being disconnected by the phone, press the multifunction button within 10 minutes to reconnect.

Reset the pairing
When in the paired state, continuously press the multifunction button for 5 times to clear the existing pairing information of the headphone and reenter the pairing state.


Charging the headphone

  • The headphone’ s red light is on
  • The headphone’ s blue light is on fully charged
  • The headphone is fully charged about 1.5 hours


  1. Do not listen for a long time at a high volume level, preventing injury to hearing
  2. For traffic safety, do not use the headphone while driving or cycling
  3. The headphone only can be charged with DC5V charger, using a fast charger that more than DC5V or charger with DC5V more than 1.5A will cause overheat or fire;
  4. Do not expose the headphone to high temperature or expose it to sunlight for a long time;
  5. The storage temperature of the headphone is from -10°C to 40°C;
  6. Please fully charge the headphone after a long-term placement, and ensure to charge every 3 months;
  7. Please clean the sweat first if there is any on the buttons + and”-” to avoid affecting the operation sensitivity of the headphone.


  1. Please contact us if any problems, we will provide you professional service
  2. Warranty is only covered by the first year of purchase. Free repair service if the failure is caused by product quality.
  3. Please provide the product warranty card and the Corresponding order number so that we can better solve the problem for you.

Product Parameters

  • Model: BE09
  • BT Version: V5.0
  • Charging Voltage: DC5V
  • Battery Capacity: 250mAh
  • BT Frequency Range: 2.402-2.480GHz
  • Audio Frequency: 20Hz-20KHz
  • Speakers Size: O14.2mm
  • Impedance: 320+15%
  • Transmission Range: 10m
  • Sensitivity: 115dBt3dB
  • Play Time: About 15 hours
  • Headphone’s Charging Time: About 1.5 hours

FCC warning

Any 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. 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.

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:

  • 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.

The device has been evaluated to meet general RF exposure requirement. The device can be used in portable exposure condition without restriction

Documents / Resources

Langsdom Opetec Race 4 Directional Sound Headphones [pdf] User Manual
BE09, 2AZDD-BE09, 2AZDDBE09, Opetec Race 4 Directional Sound Headphones, Directional Sound Headphones, Sound Headphones, Headphones

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