Power Acoustik CPT1-4000D Mono Block 4000 Watt 1 Ohm Stable Class D with Dash Mount Remote Gain Control, Phase Switch and Selectable 45Hz Bass Boost 1 Ohm Load Stable Class D Selectable 45Hz, 6/12dB Bass Boost Variable 12dB 20-50Hz Subsonic Filter Bridged Synchronization (strap amps together for double power!) MOSFET PSU Transistors Regulated PWM Power Supply Three-Way Protection Circuitry (short, thermal & overload) Pre-Amp Outputs 200mV-8V Low Level Inputs