Soundstorm Small 4CH Amplifier 400WSound Storm Laboratories Evolution Series Class A B 4 Channel Amplifier, 300W RMS 400W MAX Black Finish 300 Watts RMS 400 Watts MAX 75 X 4 RMS @ 2 ohms 38 X 4 RMS @ 4 ohms DIM (WXHXL) 9"e; x 1. 75"e; x 7. 5"e; 1 x 15A Fuse 2 Ohm Stable MOSFET Power Supply High and Low Level Inputs Thermal and Speaker Short Protection Soft Turn On Circuit Power and Protection LED's High Low Pass Crossovers