Rockford Fosgate PBR300X4 Punch BRT 300-Watt Ultra Compact 4-Channel Amplifier Four-channel, 4-ohm (only) amplifier with 75 Watts x 4 @ 4-Ohms RMS power rating and 300 watts RMS total power. The suggested alternator is 75 A and the recommended fuse is 50 A Designed for stereo front/rear systems that require little space--just 1.53 x 4.25 x 6.75 inches High- and low-level inputs with variable 4-6 volt hi level DC offset voltage input turn-on control Selectable 80Hz LP/AP/80Hz HP filter @ 12dB/Octave One-year limited warranty