gold plated RCA jacks and output connetors switch able electronic crossover simultaneous mono/stereo operation capability gain level control soft dalayed remote on/off circuit frequency response range :20Hz-20KHz T.H.D.C rated Rms power less than 0.8 percent RMS output :250W*4 OUTPUT IMPEDANCE:4 DC power:11.5-14V Signal /noise radio:more than 90dB SIZE:150(L)*300(W)*82(H)