The first truly wireless headphones in the EXTRA BASS series, the WF-XB700 offers deep, punchy sound. These headphones are equipped with a large driver unit 12 mm in diameter to deliver both seriously powerful, punchy low-end sound and clear high-end sound. IPX4 rating water resistance makes these a perfect pair for working out—the user can enjoy great quality music without having to worry about the sweat. The earbuds are ergonomically designed for a secure, comfortable fit.