Portable, RoadKing RK400 Noise Cancelling Bluetooth Wireless Headset with Dual Mic Design Consumer Electronic Gadget Shop Noise Cancelling Technology, Dual Mic Design Virtually Eliminates 100% of Background Noise Up to 66' (20 Meters) Operation Range Up to 30 Hours Talk Time with Up to 900 Hours Standby Time Voice Recognition Answers or Reject Calls by Voice Command