Autotek SMA1100.4 1100W 4-Channel Street Machine (SMA) Series Amplifier Features: Low Noise Pre-Amplifier Low Level RCA Inputs and Outputs Easily tie into OEM audio systems Class A/B Circuitry Designs Fully Adjustable 12dB Crossovers PWM MOSFET Power Supply Nickel-Plated Brass Screw Down Connectors LED System Protection Circuitry Aluminum heatsink with a black finish Symmetrical Profile Type: Amplifiers RMS Power: 2 ohm: 4 x 275 4 ohm: 4 x 150 Bridged Power: Bridged @ 4 ohm: 2 x 550 Frequency Response: 10Hz-45KHz THD: SNR: > 90db