Light weight and cool design. ?Dimensions (63.5 x 28.5 x 10 mm). ?Advanced Bluetooth frequency-hopping technology for interface-free use of mobile and music. ?Built-in Hold key and Microphone. ?Control the play, pause, stop, skip, previous song and volume of your player directly from this device (requires Bluetooth audio adapter). ?Works with iPod, PSP, most MP3 players and other audio devices. ?Standby time: up to 100 hours, Play time: up to 5 hours, Talk time: up to 6.5 hours. ?Charging time: 2~3 hours. ?Weight: 19g.