... DVD and cassette player,USB,SD jack 2.High sensitive wireless mic 3.Built-in 18V rechargeable battery Portable ampBuilt -in ... Dual channels UHF or VHF fix frequency wireless system optional (UHF have 50 to 70 wireless transmission distance,VHF have 20 to 30 ... card,MP3,MP411.Built-in advanced receiver modular system with two wireless mics (handheld ,lavalier ,and clip type optional )2 wired microphone ...