4 Channel MOSFET Bridgeable Amplifiers With Built In Crossover. Maximum power output. @ 2 Ohms 225 Watts x 4 Channels = 900W. Total channel output power: 110W x 4CH 2 Ohms (440W) less than 0.5% THD. 75W x 4CH @ 4 Ohm (300W) less than 0.5% THD. Bridged 220W x 2 CH @ 4 Ohms. LPF (low pass filter) variable. HPF (high pass filter) variable. High and low adjustable level input. MOSFET DC-DC switching power supply. LED indicated power status. Built-in protection against short circuit and high temp. Tri-mode. Bass boost (0dB-18dB). Auto power on/off by remote (+12V). Dim (WxHxD) mm: 287 x 64 x 389