USB bluetooth dongle with 3.5mm jack. can be connected with MP3,PMP, computer. 2 in 1 USB & 3.5mm bluetooth dongle/2 in 1 bluetooth adpter3.5mm jack; can be connected with MP3 player, computer and PMP; Operation Distance: Within 10m Embedded rechargable Li-batteries:300mAh Normal charging time: 2~2.5 hrs Calling time: 12hrsStandby time: 200hrs Size:85*32*15mm Weight: 18.8g