1. The DC protection can't work with the Digital Power Amplifier board or BTL Circuits 2. The horn protection board has the functions of power-on delay (about 3 seconds) and DC protection (control voltage is about 1V). The board circuit is simple and safe and reliable. 3. With LED light indication, it lights up when working, and it is extinguished when protection starts. It adopts double parallel OMRON relay, which is suitable for most power amplifier boards. 4. This protection board is powered by AC 12-18V.It must be powered by a separate power supply. Otherwise, the power amplifier board may be . Can withstand power: 50W-300W Protection board size: 68 x 55 MM Maximum Power Per Channel: 101-130W Model Number: UPC1237 Channels: 2 (2.0) Type: Home Amplifier color:Photo color Material:ABS Capacitors are random and do not affect use. No specification accepted Package Contents: 3 x Speaker Protection Board