Easy to install, the TDA7294 chip is designed on the same side, there is no obstruction in the front, and it is very convenient to fix the chip. A 100P capacitor is added to the input end. Many board diagrams save trouble and do not add it. It must be added in standard circuits. Strictly abide by -point grounding principle, and separate high-current ground and low-current ground layouts, making the low noise of this board almost inaudible. The relay is powered by a voltage stabilizing block and is equipped with a heat sink, making it stable and reliable. Generally, power amplifier boards use current-limiting resistors to power relays, which are easily affected by the input voltage. If the input voltage is high, the relay will generate a lot of heat. If the input voltage is low, the relay will not close tightly and the contact resistance will be high. Note:Due to different production batches, the appearance color is slightly different, which does not affect the use. Colour:As Shown Material:Metal+Plastic Package Contents: 1 * Port 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.