Compact 4-channel amplifier: 45 watts RMS x 4 at 4 ohms, not rated for 2-ohm operation and non-bridgeable.  Selectable high- pass filters (60, 80, 121 Hz at 12 dB/octave. Class D amp technology (frequency response: 20-20,000 Hz).  Weather-resistant aluminum chassis. Preamp and speaker-level inputs: wire-to-RCA adapters for speaker level inputs included. Wiring and hardware not included with amplifier: 10-gauge power and ground leads recommended. Fuse rating: 15A, Dimensions: 9″W x 1-3/4″H x 3-5/16″D.