With ultra-high sensitivity of 107d B/m W, these headphones will allow you to push volume right up to the max without sacrificing the clarity of the song. A 12mm neodymium driver allows the same sensitivity & low distortion as a 16mm driver, just smaller. With the small size these headphones are able to sit neatly at the back of the ear for an extra comfortable fit & enhanced sound isolation. The casing around the headphone bud is brass, which is an excellent metal for suppressing unwanted vibrations whilst keep sound stable.