Solid Bass wireless over-ear headphones with Bluetooth wireless technology for use with compatible smartphones and listening devices. Mic and volume/control buttons built into ear cup. Pairs with up to eight Bluetooth wireless devices. 53 mm drivers and built-in headphone amplifier. Double Air Chamber System reproduces deep, rich bass. Powered by a lithium polymer rechargeable battery (6 hours continuous use, 200 hours standby); USB charging cable included.