The Rockford PBR400X4D is a full-range 4-channel amplifier designed for stereo front/rear systems that requires little space. The BRT (Boosted Rail Technology) is an ultra efficient design that generates 400 Watts of power! The BRT also has a variable hi-level DC offset turn-on circuit for easy installation into any OEM system. Great for motorcycles and recreational vehicles. The Punch PBR400X4D is a full-range 4-channel amplifier that is small enough to fit in just about any application but packs a Punch with 400 Watts RMS of power! The BRT (Boosted Rail Technology) allows the PBR400X4D to be compact and efficient while providing power on demand. The BRT also has a variable hi-level DC offset turn-on circuit for easy installation into any OEM system. Our integrated level setting technology called C.L.E.A.N (Calibrated Level Eliminates Audible Noise) helps to quickly setup the amp output controls by removing the guesswork & eliminating any speaker damaging distortion. This amp is ideal for UTVs, motorcycles, or compact mobile installs, not only because of its size, but because it doesn’t suck a lot of juice from your electrical system.