The board uses six disassemble amplifier tubes, 4 responsible for the left and right channels, the other two connected to BTL circuit for subwoofer use, wiring is very simple, especially for DIY.Working voltage: AC double 18-24V 100W transformer output power: 3*80WMax subwoofer output: 120WMax Left and right channel output: 100W+100WLoad impedance: 8ohmFrequency response: 20Hz-30KHzDistortion: 1%size:15.8x16.7x4.2cmMaterial:ABScolour:Photo ColorPackage Contents:1 * Audio Amplifier BoardOnly the above package content, other are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.