Lanzar RDA753D Reign 4000 Watt 3-Channel Compact Class-D Full Range Hybrid Amplifier (Discontinued by Manufacturer) 2 x 280 Watts + 1 x 750 Watts RMS @ 4 Ohms - Double Sided SMT Circuit Board - Variable Bass Frequency : 40-100Hz - Advanced Protection Circuitry - Dimension : 9.8" (L) x 6.1" (W) x 2.7" (H) 2 x 550 Watts + 1 x 1500 Watts MAX @ 4 Ohms - 2 Ohms Stereo Stable - Phase Adjustable : 0 Degree - 180 Degree - Soft Turn On/Off 2 x 400 Watts + 1 x 1100 Watts RMS @ 2 Ohms - LPF Variable Crossover : 30Hz-200Hz 24dB/Oct - Dash Mount Remote Subwoofer Control - Frequency Response : 20-40K Hz 2 x 1100 Watts + 1 x 1800 Watts MAX @ 2 Ohms - HPF Variable Crossover : 50Hz-250Hz 12dB/Oct - Nickel Plated Low Level RCA Input - S/N Ratio &gt; 95 dB New Compact Design Based on Class-D Technology - Variable Bass Boost : 0-18dB - Power Protection LED Indicators - Fuse : 35A x 2