Sennheiser's Signature Sound Enjoy your favorite music like never before with our audiophile-inspired 42mm transducer system that delivers brilliant dynamics, clarity and musicality. _ New Adaptive Noise Cancellation and Transparency Mode Our next generation Adaptive Noise Cancellation automatically adapts to ambient noise so you can stay immersed and hear every detail, even in noisy environments. Need to hear an announcement on the train or a question from your colleague? Just activate the versatile Transparency Mode at a touch to hear outside sounds without removing your headphones. _ Premium Look & Feel The M4’s lightweight design features a padded headband and deep, yet soft, cushioned earpads to ensure exceptional and long-lasting wearing comfort. Meanwhile, the low-friction hinge mechanism easily adjusts to give you a great fit without placing excess pressure on your head. _ Up to 60-hour Battery Life Keep on listening while you fly around the globe, with up to 60-hour battery life and fast charging capability that provides a further 6 hours listening in just 10 minutes. _ Features Sennheiser Signature Sound Customized sound Adaptive Noise Cancellation Transparency Mode Premium Comfort Top-Tier Battery Life Crystal-clear Calls _ Specification Connectivity : Bluetooth 5.2 compliant, class 1, 10 mW (max) Supported Profiles : A2DP, AVRCP, HFP Codecs : SBC, AAC, aptX, aptX adaptive Transducer principle : 42mm diameter Speaker frequency range : 6 Hz to 22 kHz Speaker sensitivity : 106 dB SPL (1 kHz / 0 dB FS) Active Noise Cancellation : Hybrid Adaptive ANC Microphone principle : MEMS Microphone pick-up pattern : 2 mics per side, beamforming for noise reduction Battery type : Built-in Lithium-Ion rechargeable batteries 700 mAh _ Free : Headphone Stand