Features: This product is a device compatible with Bluetooth that combines receivers and transmitters two-in-one. Easy to operate - Free to send and receive all audio signals. BT receiving mode allows you to transfer music from your phone to a traditional home audio device. It is more convenient to send a TV, CD player, MP3 or other audio source to a BT speaker or BT headset through the product's BT transmission mode. Because the product uses low-latency technology, it also supports real-time transmission of online games, TV, and movie sounds. This product has a built-in rechargeable battery, long battery life, and expands the transfer function of various audio devices. Specification: Optional Color: Black, White Compatible with Bluetooth version: 4.2 Compatible with Bluetooth protocol support: A2DP and AVRCP Support multi-format decoding: MP3, WAV, WMA, APE, FLAC Transmission distance: >20M (open area) Charging input voltage: DC5V Power supply: 3.7V Power consumption: play less than 20 mA, connect standby 0.6-4.5 mA, shut down within 2 microamps Working time: >10H Charging time: 2H Signal to noise ratio: 95db or more Support one for two: TWS function Input / output connection: 3.5MM stereo headset socket Compatibility: The receiving end is compatible with all brands of mobile phones for Android system and for IOS system; the transmitting end is compatible with for CSR/LeiJap/Airoha/Vimicro/AnyKa/RDA/Jianrong/Jieli and other BT solutions. Package list: 1 * 2-in-1 Receiver Transmitter 1 * USB Cable 1 * 3.5MM Audio Cable 1 * English Manual 1、This product is a device compatible with Bluetooth that combines receivers and transmitters two-in-one. 2、Easy to operate - Free to send and receive all audio signals. 3、BT receiving mode allows you to transfer music from your phone to a traditional home audio device. 4、Because the product uses low-latency technology, it also supports real-time transmission of online games, TV, and movie sounds. 5、This product has a built-in rechargeable battery, long battery life, and expands the transfer function of various audio devices.