The Sennheiser CX 400-II Precision ear-canal headphones offer natural dynamic sound reproduction, bass-driven sound, and excellent sound suppression. Get ready to upgrade your sound quality thanks to Sennheiser's superior musical reproduction. This brilliant sound is achieved with neodynamic magnets that are tuned precisely to produce life-like natural sound. To block out the noise from the outside world and guarantee a brilliant sound experience, the CX400-II earphones are equipped with adaptors that will enable a snug fit. Three different sizes of these silicone gel ear-adaptors are include by Sennheiser to ensure the perfect fit for you. For ease and comfort the CX400-II have a volume control attached to the cable. And when the cable is in the way, the cable winder will allow you to "tidy-up" easily and quickly and stow these gems in the included carrying pouch.