Power supply: dual DC power supply +/- 58-+/- 70V The rated output power: 500W (+/- 65V power supply, 4 ohm load, distortion 10%) Efficiency: equal 90% : 90dB Frequency range: 20Hz-20KHz Material: CCL Colour: blue The total harmonic distortion: 380W (+/- 65 power 4 ohm speaker, distortion Less than 0.1%) 280W (+/- 65 power 8 ohm speaker, distortion Less than 0.1%) Speaker: 4-8ohm Voltage Magnification: 36 times Input sensitivity 1.5V (RMS) Output short circuit protection: Yes That output DC bias protection speaker protection: Yes Over-temperature protection: Yes, radiator FET temperature higher than 100 Celsius , turn off the output Product Size: . 100 x 50 x 30mm/3.93 Inch x 1.96 Inch x 1.18 Inch Net weight: .100g/pcs Package Contents: 2 x Digital Amplifier Module Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.