Feature 1Professional Manufacturing: It is a 500W class D sound amplifier, mainly used in home theater and with speakers. 2Circuit Optimization: Single channel class d sound amplifier board adopts circuit optimization and adds speaker relay protection. 3Unique Design: Digital amplifier board: can turn on the delay, turn off the instantaneous break, effectively solve the switch on and off the shock sound. 4Relay Power Supply: Digital stereo power amp module with its own relay power supply, external 110V 220V AC can be. 5Premium Material: Single channel class d sound amplifier board using PCB material, high density, safe and reliable, aging resistance.Item Type:DigitalPowerAmplifierBoardMaterial: PCBPower Amplifier Plate Size: Approx. 105x43x28mm / 4.13x1.69x1.10in Supply Voltage: Dual DCPower Supply 45 - 70V (Recommended +-65V Power Supply Can Be)Rated Output Power: 500W (65V Power Supply 4 Ohm Load, Distortion 1%)Efficiency: >= 90%SNR: 90dbTotal Harmonic Distortion:380W (70 Powered 4 Ohm Speaker, Distortion <0.1%)280W (70 Powered 8 Ohm Speaker, Distortion <0.1%)Frequency Response Range: 20Hz-20KHzHorn: 4-8Voltage Amplification: 50 TimesInput Sensitivity 1V (RMS)Output DC Bias Protection I.E. Horn Protection: Yes .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List1 x DigitalPowerAmplifierBoardNotePlease allow some error in manual measurement.