Monster Cable RadioPlay Car Stereo Wireless FM Transmitter (MBL-FM XMTR) Easy one-button FM channel selection with eight available channels. 24k gold contacts for maximum corrosion resistance and power transfer. Plugs into your car's 12v cigarette lighter. No batteries required. Transmitter utilizes FM channels: 88.1, 88.3, 88.5, 88.7, 88.9, 89.1, 89.3, 89.5