Bluetooth Version : 5.0 Driver Size : 40 mm Impedance : 32 Oh Sensitivity : 19db Frequency Response : 20hz 20khz Wireless Operating Range : Up To 15m Built In Rechargeable Battery : 200mAh Lithium Polymer Battery : A Level With Protective Plate Working Time : Up To 10 Hours At 70 Volume StandyBy Time : Appro. 200 Hours Charging Time : 2.5 Hours