Optional matching supply:The connector is a standard 55MM jack, the same as most notebook supplies.The supply for the board is critical. The higher the voltage, the higher the current and the better the output .If you only have 12V 1A, it can driver 3-4 inch subwoofer . If you are above 19V 5A, there is no problem driving the 8-10 inch subspeaker, and the supply must be highly valued.Digital subwoofer amplifier board with preamplifier op amp NE5532 buffer matching.The product uses the new US TI company TPA3116D2 high-performance amplifier chip as the core, DC single supply 8-25V wide working voltage, 50W (left channel) + 50W (right channel) two-channel output, the efficiency is up to 90%. Can use switching supply, laptop switching supply, battery or car supply, etc... supply range: DC8-25VNumber of channels: mono(Subwoofer output)Output : 100WTurn the knob to the bottom to turn off the stateColour:GreenMaterial:plasticSize:75X60MMPackage Contents:1 * Amplifier BoardOnly 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.