Form and function. I the transparent casing. The play/pause buttons come particularly handy as the default iPhone earbuds do not have this feature. The earphones have a sound value that opens when the volume falls below 40 decibels, meaning that it allows you to hear more ambient sound. When the volume is turned up above this threshold, the valve closes. This is particularly useful because you don't have to take off the headphones to hear outside sound; you merely need to turn down the volume.