The iRiver Mobile FM Transmitter broadcasts a powerful signal allowing you to listen to your iRiver player or other portable audio device through your car stereo. It transmits to any FM frequency making it easy to listen to your music on any FM signal you choose. PRODUCT FEATURES: Blue LCD display; Plugs into any standard car power socket; No batteries needed; Transmits to any FM station (88.1MHz – 107.9MHz); Works with any audio device (plugs into the headphone jack of your player).