The Skar Audio SK-M4004D is an ultra compact, “mini”, Class D full-range, four channel car speaker amplifier. The SK-M4004D was engineered to be compact, but provide the power and reliability expected out of larger amplifiers. Featuring a high speed MOSFET power supply, and an efficient Class D design, this amplifier is powerful, reliable, and extremely versatile. The SK-M4004D makes for a great amplifier in applications where space is limited but power cannot be sacrificed. In addition, this four channel amplifier features high level input connections for those installations that lack an RCA connection. In addition to the high level inputs, this amplifier also utilizes an adapter harness for the speaker outputs allowing for an easier and cleaner installation. Further adding to the feature rich list of this amplifier are its high pass / full-range / and low pass user controls, as well as having 4-Way Protection Circuitry Built-in (Thermal, Voltage, Speaker, DC). Utilizes 8 Gauge Power and Ground Input Terminals. Amplifier’s dimensions: 7.9in x 4.6in x 1.7in (L x W x H). Frequency Response: 10Hz – 40kHz.