Orion  XTR1000.4   Four Channel Car Audio Amplifier with Built-in High And Low Pass Filters, Bass Boost, Tri-Mode Capable RMS Power Rating: 4 Ohms: 165 Watts x 4 chan. 2 Ohms: 250 Watts x 4 chan. Bridged, 4 Ohms: 500 Watts x 2 chan. Fuses: 3 x 40A Variable high-pass filter (50-2,000 Hz, 12 dB/octave). Variable Low-pass filter (50-2,000 Hz, 12 dB/octave). Subsonic Filter (12 dB at 24 Hz) Frequency response: 20-20,000 Hz Dimensions: 9.3"W x 2.5"H x 14.3"L.