This two-in-one BT receiver and transmitters can help cable devices and BT devices connect, providing users with a fine-quality experience. High fidelity audio output interface, optical fiber interface and 3.5mm audio interface and RCA red white conversion interface, easy to realize different power amplifier audio equipment BT transmission mode (TX): it can convert cable audio into BT signal, transmit it to BT device for output, and help to connect the computerand 39 s TV with BT speaker, BT headset, etc. BT receiving mode (RX): it can also receive BT signal and transmit it to wired audio through BT signal connection, such as connecting BT mobile phones with speakers, power amplifiers, etc 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 peopleand 39 s rest. (in TX mode) Connect the audio 3.5mm audio interface, the speaker without BT function can also play wirelessly. (in RX mode) Support one connects two functions, can link two BT headsets, share the same music or watch the same movie Long battery life, it can be used while chargings, which is convenient Long-distance transmission, in the case of no obstruction, can be transmitted freely in the ranges of about 10m High-performance BT chip, stable transmission, strong signal, low delay, fine quality sound quality Small size, easy to carry, plug and plays, easy to use LED indicator light can show different working states Specifications: Material: metalandplastics Battery: 3.7V, 300mAh Output interface: 3.5mm audio and fiber optical Working ranges: 10m (without any obstacles) Chargings times: about 2h Use times: TX mode: about 8h, RX mode: about 7h Frequency ranges: 2.402GHz - 2.480GHz Item size: 64.58 x 64.58 x 18mm or 2.5 x 2.5 x 0.7in Item weight: 48g or 1.7ounce Instructions: 1. Connect the optical fiber port or AUX interface of the product to the device, select the TX or RX 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 RX 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.