Bluetooth V5.1 ensures stable connection 40mm NdFeB driver delivers detailed and powerful sound Up to 30 hours audio playback Soft over-ear pads for all-day comfort Simple design for an elegant look and feel Connection with two Bluetooth devices simultaneously supported 3.5mm audio cable included for wired connectionBluetooth version V5.1 Audio codecs SBC Driver unit Φ40mm NdFeB driver Playback time about 30 hours Charging time about 3 hours Battery capacity 350mAh Frequency response 20Hz-20kHz Sound pressure level 96±3dBSPL Impedance 32Ω Charging port USB Type-C