Wireless New Generation FM Transmitter desinged for RCA M6204 with Powerful Compact Car Charger Included Full FM frequency spectrum is available and is user selectable in 0.1MHz increments from 88.1 to 107.9 MHz. Advanced Digital PLL sound coding maintains stable and high quality sound. Specification: Input Voltage (12-24 vDC), Cable length (50 inches), Transmitter Dimensions (2.25 X 1.25 X .25 inches), Circuit Design (RCA M6204 Specific) Car charger includes smart technology circuit architecture to provide precision voltage and resistor regulation specific to the RCA M6204. Protects the internal battery longevity by modulating the charge in a safe and efficient manner. FM Transmitter has an integrated long life rechargeable lithium battery pack. Device can be used while connected to power or wirelessly via internal battery. Comprehensive input range of 12-24VDC to support a wide variety of vehicles (both foreign and domestic). Works great on boats and RVs too!