TOOGOO(R) Sports Wireless Bluetooth 2.0 Headset Earphone Headphone Earphone for Cellphone PC Built in Microphone Portable behind-the-head wearing design, convenient for sports. Allow you answer or reject phone calls anytime and anywhere. Built in Microphone for Handsfree Cell Phone use or chatting on QQ, MSN. Support format: MP3 WMA System requirement: Windows 98 or above