FREQUENCY RESPONSE:20Hz~20kHz BluetoothBluetooth V5.1 Impedance 32Ω Sensitivity:100dB Supporting ProtocolHSP HFP A2DP AVRCP Connecting distance10m Battery capacity1400mAh rechargeable battery Working time55 hours Standby timeabout 800 hours Charging timeabout 3 hours Charging inputDC 5.0V=500mA Length (cm): 19.0 Width (cm): 9.0 Height (cm): 23.5 Net Weight (kg): 0.39 Gross Weight (kg): 9.00 Pieces per box: 20