... : V2.0,V1.2,V1.1 standard, Support A2DP,AVRCPWith 3 buttons: Prev/vol-, Play/Pause, Next/vol+ ;Compatibility: All Bluetooth Enabled ... affect range of device)Working time: 16 hour Working Voltage: 3.3V-4.2V Average Working Current: 80MA Charge time: 4 ... D type Digital Power Amplifier Built-in battery: Li-polymer 3.7/650mAh Out put : 3W Automatic off power function: 5 ...