SallyBest&reg; USB SD DVD MP3 FM Radio Car Stereo Amplifier 20W+20W Remote Control Mini HiFi 2 Channel Digital Display Power Player for Vehicle / Boat / Motorcycle / Homing Using Can play U disk SD/MMC card for music and FM stereo radio, support MP3 music format.(USB+SD+FM). Selected high-power four-channel professional power amplifier integrated circuits, minimal distortion, strong power. Filtering and anti-large-capacity power circuit. DSP sound field pattern of the four, two main channel output.