1. Power supply: dual DC power supply 58V to 70V 2. Rated output power: 500W (65V power supply, 4 ohm load, 10% distortion) 3. Efficiency: greater than or equal to 90% 4. SNR: 90dB 5. Total harmonic distortion: 380W (65V power supply, 4 ohm speaker, less than 0.1% distortion); 280W (65V power supply, 8 ohm speaker, less than 0.1% distortion) 6. Frequency range: 20Hz - 20kHz 7. Speaker impedance: 4-8 ohms 8. Voltage gain: 36 times 9. Input sensitivity: 1.5V (RMS) 10. Output short circuit protection: Yes 11. Output DC bias protection: Yes 12. Over-temperature protection: Yes, output shuts off when radiator FET temperature exceeds 100C Color: As shown in photo Material: ABS Size: 98 x 43 x 30mm Package Contents: 1 x Digital power amplifier board Usage precautions: 1. Rated supply voltage is 65V, within 58V to 70V range; do not exceed 70V. Ensure correct polarity. 2. Recommended power supply: 65V 3. Recommended speaker: 4-8, 10-18 inch 4. Carefully check wiring before applying power. Package includes only the items listed above; other products are not included. Note: Lighting and display settings may cause slight color differences between the image and the actual item. Measurement error allowed is +/- 1-3cm.