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 calls Large driver with titanium diaphragm delivers crystal-clear sound Low latency for game mode gives players an immersive gaming experience Up to 49 hours continuous playback Lightweight headset assures comfortable fit *Please connect W820NB with the audio output device by Type-C cable to enjoy Hi-Res audioBluetooth 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