The speaker protection board is designed and manufactured with UPC1237 special chip, with power-on delay and DC protection functions, instant shutdown function, and comprehensive protection of your expensive speakers! The sheet material is sprayed with tin foil made of a 1.6MM thick high FR-4 board. The 10A relay has a loose sound quality, and its resistance ring is film resistor with copper feet. And with red power indicator light, power relay for about 3 seconds, indicating green indicator light, working indicator light. The protection board uses a single power supply voltage of AC 10V-18V, DC 12-24V, and can bring a group of power supplies to the amplifier board. Please try to use conditional winding or separate power supply. The mute delay starts, and the shutdown speed is turned off. The midpoint potential protection of the amplifier, the DC midpoint from the control point 0.7V. All finished boards have been well debugged and power tested. size:6.5x5cm Material:metal colour:As shown Package Contents: 2 x Protection Circuit Board Only 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.