SoundQubed 4500W Mono Block Amplifer 1 ohm Stable Remote Gain Knob with clipping light included Daisy Chain connection of two amplifiers stable down to 2 ohms Four way protection circuits: Speaker shorts, DC offset, High/Low voltage, Thermal protection Double sided boards with high current MOSFET switching devices 24db/oct slope crossovers, Fully adjustable Low Pass Filter and Subsonic Filter