Enjoy music for days with the Sennheiser Momentum 4 Wireless Gray. These headphones have a 60-hour battery life, so it lasts very long on a full charge. Is the battery empty? Charge it for 5 minutes to get 4 hours of use. Thanks to the high-end noise canceling, ambient noise is strongly reduced, so you're much less bothered by your surroundings. This way, you won't turn your volume up too loud, even in the most noisy spaces. In the Sennheiser Smart Control app, you personalize the sound reproduction with an equalizer. Add extra bass, accentuate treble, or pick another type of sound so you can listen to a personalized sound. Note: when you charge the headphones, the first 10 minutes the lights aren't on. This makes it seem like it doesn't charge, but it does. This problem will be solved soon with a software update.