Westone W40 Quad-Driver with 3-Way Crossover In-Ear Monitor Headphone is designed for the serious audiophile to provide an ultimate experience in sound reproduction. It is used in various devices such as for iPods, tablets computers, field recorders, smartphones, and more. This quad-driver headphone features a frequency response of 10 Hz to 18 kHz. It uses four balanced-armature drivers in conjunction with a 3-way crossover to provide another level in the listening experience. It features 25 dB passive noise attenuation to suppress outside noise. The W40 replaceable cable is a braided EPIC cable.