BLUETOOTH ADAPTER 4. 1 RECEIVER: Built with Bluetooth 4. 1/HFP/HSP/A2DP/AVRCP to smart Your life that you can enjoy music and hands-free calling from your smartphone in premium-quality sound. Up to 33ft connection ranges low signal delay. DOUBLE LINKS & WIDE COMPATIBILITY: Portable Bluetooth Receiver can connect two Bluetooth devices at the same time. And it also could compatible with most smartphones and Bluetooth electronics, ideal for home or vehicle audio systems and wired headphone. EASY CONTROL & SATISTACTION GUARANTEE: 3 buttons with built-in microphone allow you to turn on/off, play/pause, adjust volume/track, answer/reject/hand up calls at will, which guarantees safety while driving. Come with a user manual, you can play/pause/skip music/answer phone calls/redial the last called number or control music on the receiver. LONG WORKING TIME: Compact, yet durable Wireless bluetooth receiver provides up to 6~8hours of continuous audio playback or 100 hours on Standby. only about 50 minutes charging time(NOTE: not charge for a long time. ) DESIGN: This special Bluetooth receiver with clip design, easy to carry, get rid of the tangle cables, so you won't lose it any more, it is convenience to turn your car speaker Into Bluetooth speaker hands-free Calls /GPS/Music/Driving Safety . Specification: Colour: Black Bluetooth version: 4.1 + EDR Receiving distance: 33FT Frequency response range: 20Hz-20KHz Talk time: 6~8 hours Charging time: about 50 minutes Output power: 30mW Output 3.5mm audio jack