4 Channel MOSFET Bridgeable Amplifier, 2 Ohm Stable, Max Power:4 x 180 Watts, RMS: 4x 60 Watts, Line Through to Daisy Chain Amps for Multiple Amplifier Installation, Signal to Noise Ratio: 85dB, Frequency Response: 20hz -30khz (1dB).  In-built Bass and Treble Controls.