The ATH-SR30BT wireless over-ear headphones deliver the exceptionally pure audio of Sound Reality in a convenient wireless design. With exclusively designed 40 mm drivers and a dual-layer isolation housing structure that optimizes phase and transient response youll enjoy powerful full-range audio reproduction from a Bluetooth® wireless signal. Whats more the internal battery provides a remarkable 70 hours of continuous use on a full charge so for all practical purposes the music never has to stop!