We are manufacturer, professional amplifier. 1, 450W. 2,USB playing it. radio station, SD card. 3, 70/100V, 4-16ohm. 4, more ModelRated powerOutput modeInput sensitivityS/n ratioFred ResponsePower workDimensionsMC-2450450W70-100V4-16Ω500mv>85dB60Hz18KHz±2dBAC220V±10%/50Hz 90 ×485 ×4301. Built in reliable protection circuit for shortcut and overload2. Input level indicator in 5 LED3. There are 3 ...