Audio-Technica ATH CKS55XBT Solid Bass Headset, Red/Black (ATH-CKS55XBT) Bluetooth wireless technology with in-line mic and controls Remembers a few devices and automatically connects with the last paired device Double air chamber system naturally expands bass output for powerful bass, without sacrificing audio clarity Direct diaphragm drivers Two-position post maximizes sound isolation, while providing a better fit