The speaker protection board using UPC1237 dedicated chip design and manufacturing,has a power-on delay and DC protection,instant shutdown feature,all-round protection of your expensive speaker Sheet 1.6MM thick high-FR-4 board manufacturing tin foil sprayed,10A relay is loose music quality, the resistance rings are gold film resistor copper feet. And with a red power indicator,power relay approximately 3 seconds,indicating that green light,the work indicator.The protection board using a single power supply voltage AC 10V-18V,DC 12-24V,you can take a group of electric power to the amplifier board.Try to use conditional independence winding or separate power supply.Mute delay ,shutdown speed off.Amplifier midpoint potential protection,the midpoint of DC from the control point of 0.7V.All finished boards are good debugging,and power test.Size:6.5x5cm/2.56x1.97inchcolor:Green + blackMaterial:ABSPackage Contents:2 x Speaker Protection Circuit BoardOnly the above package content, other products 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.