Compact Mini Size High Power Hi Fi USB MP3 SD Stereo AMP Amplifier Remote Control For Home, Car, Motorcycle, Van, Boat Motor bike And So On Out-Put Power :2X20Watts (Peak Music Power) In Put Power: 12V-18v 3-5A DC (5.5mm outlet/ 2.1mm centre hole jack) Speaker Impedance:4-16 ohm Supports USB flash/jump drive and SD/MS card (max 16GB SD card) Interfaces: SD/MMC/MS + USB + L /R + 3.5 mm