1、Audio output interface: optical fiber interface + 3.5mm audio interface + red white conversion interface, easy to realize different power amplifier audio equipment. 2、BT transmit mode (TX): it can convert cable audio into BT signal, transmit it to BT device for output, and help to connect the computers TV with BT speaker, BT headset, etc. 3、BT receiving mode: it can also receive BT signal and transmit it to wired audio through BT signal connection, such as connecting BT mobile phones with speaker, power amplifier, etc. 4、It can be connected to the TV, and transmit the sound to the headset through BT to watch the TV, so as to avoids affecting other people's rest. (in TX mode) 5、Connect the audio 3.5mm audio interface, the speaker without BT function can also plays wirelessly. 6、Support one connects two function, can link two BT headsets, share the same music or watch the same movie. 7、Long battery life, it can be used while chargings, which is convenient. 8、Long distance transmit, in the case of no obstruction, can be transmitted freely in the ranges of about 10m. 9、High performance BT chip, stable transmit, strong signal, low delay, fine quality sound quality. 10、Small size, easy to carry, plug and plays, easy to use. 11、LED indicator light can show different working states. Specifications: Material: metal+plastics Battery: 3.7V, 300mAh Output interface: 3.5mm audio + fiber optical Working ranges: 10m (without any obstacles) Chargings times: about 2h Use times: TX mode: about 8h, Receive mode: about 7h Frequency ranges: 2.402GHz~2.480GHz Item size: 64.58 * 64.58 * 18mm / 2.5 * 2.5 * 0.7in Item weight: 48g / 1.7ounce Package size: 120 * 100 * 54mm / 4.7 * 3.9 * 2.1in Package weight: 158g / 5.6ounce Instructions: 1. Connect the optical fiber port or AUX interface of the product to the device, select the TX or Receive mode according to the needs, long press the multi-function button for about 5 seconds, and then turn on the machine. The blue light flashes slowly back to the connection mode. Wait for 10 seconds, and then the blue light flashes quickly, indicating that the product is in the normal power on and in be paired state. 2. When using Receive mode: Open BT, search ZF-380 and click connect. When using TX mode: Turn on the BT headset or BT audio to enter to be paired state, and the product will connect automatically. 3. After successful pairing, the blue light keeps on and you can starts to use it. 1 * BT Adapter 1 * Micro USB Cable