Item Type: Bluetooth Receiver Model: BT22 Colour: Black Material: ABS Function: Bluetooth Receiver Scope of Application: Most Smart Devices with Bluetooth Bluetooth Version: 5.1 Bluetooth Connection Range: Approx. 15m / 49ft Built In Battery: Polymer Lithium Battery Built In Battery Capacity: 200mAh Working Hours: 8 Hours for Receiving, 5 Hours for Transmitting Frequency Response Range: 10Hz-20KHz Signal to Noise Ratio: Less Than 110db 1、Bluetooth 1 Version: Bluetooth auxiliary adapter adopts an enhanced signal receiving circuit, which can connect quickly and provide stable and continuous audio.  2、Noise Reduction: With built in chip has AEC echo cancellation and ANC noise cancellation circuits to make the sound quality more pure and true.  3、Memory Function: Bluetooth adapter has an automatic connection memory function. After a successful connection, turn on Bluetooth again and it will automatically connect to your phone.  4、Small and Portable: This bluetooth wireless music receiver is lightweight. Small size but powerful, portable wireless music receiver bring you a better music experience!  5、Long Distance Transmission: This adapter can receive music up to 15 meters(about 49ft) away, allowing you to remote control music more conveniently.