Features: brand new and high quality Bluetooth-compatible audio receiver adapter, handsfree in car audio phone call receiving. Automatically connect back to the paired Bluetooth-compatible device when powered on With 3.5mm jack aux mp3 music Built-in 250MA rechargeable battery, environmental for protection and energy saving. Five minutes without device connection, automatic shutdown Wireless receiver adapter with microphone for stereo music Support voice broadcast caller number in car, full power playback time: about 9 hours Specifications: Bluetooth-compatible version: V5.1 Battery: Built-in 250mA rechargeable Music Playback Time: about 9 hours Support : Stereo Music DSP Technology Bluetooth-compatible Playback Sistance :within 10 Meters/33ft Size: approx 5.5X3X1.15CM/2.16x1.18x0.45in Material: ABS Transmition Rate: 1000(Mbps) Connection: AUX 3.5mm Color: Black Note: There might be a bit color distortions due to different computer resolutions. There might be size errors due to different computer resolutions. Package includes: 1PC x Audio Receiver 1PC x User Manual