SPECIFICATIONS 1>>>BLUETOOTH RECEIVER: UGREEN Bluetooth adapter 5.0 is designed for non-Bluetooth car/home stereo system with 3.5mm aux port. 10m barrier-free transmission. The back clip allows this adapter to stay wherever you want.Compliant to version 5.0 specifications, backwards compatible to Bluetooth 4.2/4.1/4.0/3.0/2.0/1.0 2>>>HiFi SOUND QUALITY: Wireless audio adapter supports Qualcomm® aptX™LL decodi ng technology to restore CD stereo sound quality. QCC chip for more stable, faster transmission and lower power consumption. 3>>>About aptX™ Low Latency : Qualcomm® aptX™ Low Latency audio ensures your Bluetooth® wireless enabled device can deliver sound in sync with visual media. It reduces delay and improves end-to-end speed of the audio transmission, resulting in a high quality, synchronised user experience. With aptX Low Latency you can enjoy the freedom of wireless for applications such as gaming and watching videos. 4>>>HANDS-FREE FUNCTION: Built-in microphone supports hands-free calling. The Bluetooth receiver has a switch button and two volume buttons. The volume buttons not only control the sound but also switch the song. 5>>>BUILT-IN BATTERY: Fully charged for 2 hours, 4-5 hours of continuous use. The Bluetooth receiver can pair two devices at a time and can switch between them freely.