The ATH-CK200BT in-ear headphones give you excellent wireless audio at a great price. The powerful 9 mm drivers deliver clear, vibrant audio from a Bluetooth® wireless signal, while the compact housings and interchangeable eartips (XS, S, M, L) provide good sound isolation and a comfortable, customizable fit. The headphones feature an in-line mic and controls, allowing you to answer calls, adjust volume and control music playback on compatible smartphones and other devices. The ATH-CK200BT's design conveniently situates the mic and controls for easy access and places the battery case on the upper back where, if desired, it can be attached to your shirt collar with the included clip. The internal battery powers the headphones for up to 7 hours (200 hours standby) and can be recharged with the included 30 cm (1') USB charging cable.