W820NB BLACK BLUETOOTH HEADPHONE W/MIC ANC EDIFIER,Hi-Res Audio standard for a rich listening experience,Active noise cancellation technology isolates unwanted noise,Ambient sound mode allows you to hear environmental sounds such as traffic or flight announcements,DNN noise cancellation technology ensures clear phone call,Large driver with titanium diaphragm delivers crystal-clea,Low latency for game mode gives players an immersive gaming experience,Up to 49 hours continuous playback,Lightweight headset assures comfortable fit,Bluetooth version V5.0,Audio codecs AAC, SBC,Driver unit 40mm dynamic driver,Playback time ANC on: about 29 hours, ANC off: about 49 hours,Charging time About 1.5 hours,Battery capacity 400mAh,Frequency response 20Hz-40kHz,Sound pressure level 91±3dB SPL,Impedance 32Ω,Charging port USB Type-C