Double-sided SMT Epoxy PCB Power Handling RMS: 65W x 4 at 4-Ohm Painted Conformal Coating PCB Board Efficiency: 80% 4-Ohm at 1KHz Multi-way Protection Circuitry (Thermal/Over Current/Speaker Short/Speaker DC Protection) Input Sensitivity: 6V-0.5V Variable High Pass Filter: 50Hz-250Hz Variable Low Pass Filter: 50Hz-250Hz Signal to Noise Ratio: >90dB Tested Voltage and THD: 14.4V and Less Than