The newly developed 12.5 mm drivers allow the ATH-CKR50iS in-ear headphones to deliver powerful, well-balanced audio with astonishing depth and clarity. The performance is further enhanced by machined brass stabilizers that absorb unwanted vibration for crystal clear mid and high frequencies, and by four sizes (XS, S, M, L) of interchangeable eartips for a customized fit and outstanding sound isolation. The in-line controller and microphone let you easily answer calls and control playback of music and video.