Superior sound, no compromise, powered by Sennheiser’s German-made 7mm TrueResponse transducers. Personalize audio with the built-in equalizer; then get pumped with Bass Boost. Up to 27 hours play time. The 9-hour battery life can be extended on-the-go up to an additional 18 hours with the charging case.Passive Noise Cancellation via the ergonomic design and 4 ear adapter sizes for optimal comfort and secure fit to keep out all outside noise. Customizable touch controls for easy control of music, calls and voice assistant on your terms. Enjoy an outstanding audio experience no matter where you are with the IPX4 splash resistant design.