This product uses a single 9-24V DC power supply and utilizes the TPA3116D2 high-performance digital amplifier chip as its core. It features a parallel bridged subwoofer amplifier and supports 120W (subwoofer output). It includes an external audio input interface, pre-amplification, and subwoofer crossover processing. It also features two potentiometers for adjusting subwoofer volume, subwoofer frequency, and on/off/master volume. It features a wide operating voltage range, a power-saving design, and an efficiency of over 90%. You can use a good switching power supply, a laptop switching power supply, a rechargeable battery, or a car power supply. The board is a pre-assembled, pre-tested board. Connect the speaker box according to the diagram, connect a suitable power supply, and correctly connect the audio source input, and you're ready to go. This board only has a mono output; it lacks treble or midrange. You can only hear a of vocals, mostly the . It supports mono and dual-channel inputs, but doesn't support high-level inputs. If the amplified signal exceeds 1W, or if the amplifier output signal cannot reach the input of this amplifier board, the output be automatically cut off. Color: Black Material: PCB+Metal Package Contents: 1* Amplifier Board with accessories (accessory colors are random) Only the above package content, other products are not included. Note: Light reflection 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.