The Sennheiser Momentum 4 Bluetooth over-ear headphones are audiophile-inspired with a 1.65" (42 mm) transducer system that delivers brilliant dynamics, clarity and musicality. Adaptive Noise Cancellation automatically adapts to ambient noise. It features outstanding battery life with up to 60 hours of play-back time with fast charging Bluetooth 5.2 compatibility. The Digital Beamforming Microphone system employs two mics on each ear cup: simply touch interface on the right ear cup for music, ANC, calls and voice assistant to ensure effortless ease of use.