Class D Digital Mono block Amplifier. Full MOSFET PWM Power Supply SMD Technology on Double Sided PCB. 8ga Power & 8ga Speaker Output Terminals High & Low Level Signal Inputs. Remote Mount Gain Control Included. Variable 35-250Hz 12dB Low Pass Filter Variable 10-50Hz 12dB Subsonic Filter Variable 0-12 dB 45Hz Bass Boost. Trimode Capable 4ohms 66w x 4ch+210w sub 2Ohms 85w X4ch+330w sub Frequency Response: 20-150 kHz. Signal-to- Noise Ratio: 70dB Damping Factor: > 250 Input Sensitivity: 200mV-6V MINIMUM SPEAKER IMPEDANCE: 2 OHM ONLY Dimension: 4.75"w x 1.5"h x 10"23