Features: 1) 5.1 channel amplifier with remote control 2) Real 5.1 channel input/output 3) 2.1/5.1 channel input interchangeable 4) Power output: a) Subwoofer: 21W (RMS) b) Satellite: 8W x 5 (RMS) 5) Speaker driver a) Subwoofer: 5.25"/8Ω, 40W b) Satellite: 3"/4Ω,8W 6) Input sensitivity: 240mV 7) Frequency response: a) Subwoofer: 20Hz -140Hz b) Satellite: 200Hz - 20kHz Outer packing: 2 sets/carton