The KS 300.4 V3 truly is that SQ packed powerhouse that you have been asking for giving you the tools to create that live in-car concert that you have been asking for without breaking the bank with ultra-high-end audiophile amplifiers. Class G and Class G/H amplifiers offer the best of all possible characteristics. Power output, distortion, efficiency, heat, noise, size are all class-leading specs with this design. But why does this class of amplifier perform so well? It's built for music, not test tones or noise. When an amplifier is playing music, even at full volume, due to its dynamic nature, it is only working above 1/2 power about 10% of the time. You only need full power during the very loud passages like the impact of a drum or the pluck of a bass string. The rest of the time your 700-watt amp is making less than 350 watts. That's where the KS amp's Class G/H design comes into play. It's like having 2 amps in one. A 400-watt amp is much smaller and produces a lot less heat. Then, in a fraction of a second, your amp becomes an 800-watt monster that is ready for any musical challenge. Features: 4-Channel Full-Range Amplifier Advanced Microprocessor Control System Non-Digital Class G/H Switching Design Code-Based Flashing Diagnostics Designed By Robert Zeff Protection Against: Reverse Voltage, Over Voltage, Speaker Short, and Thermal Overload Can Drive Highly Reactive Loads Optically Isolated Mosfet Power Supply Quiet Internal Fan Cooling 2-Channels @ 4 Ohms 220 Watts 2-Channels @ 2 Ohms 360 Watts 1-Channel @ 4 Ohms (Bridged) 720 Watts Frequency Response 5Hz - 50kHz Crossover Range 55Hz - 5500Hz Bass Boost 18dB @ 45Hz S/N Ratio CEA2006 @ 1W 91.7dB S/N Ratio @ Full Power 114.9dB Input Sensitivity (Low) 200mV - 3.5V Max Current Draw 85A @ 800 Watts 1% THD Idle Current 1.14 Amp Fuse 3 x 30 Amp Dimensions 11.25(L) x 8.0"(W)x2.375"(H)