Check the listing for details. One pair split type UPC1237 Speaker protection KIT for amplifier DIY (B6-2). Condition: New. Listed at 9.50 USD. Works voltage: AC9V-15V Each PCB Size: 65MM * 71MM Output terminal hole spacing:25mm ( Center to Center Spacing) List price is for L and R 2 channel kits or boards Features: 1 : UPC1237 as the core , with power-on delay, DC protection, power-off anti-shock. 2:Use fully sealed high-current relay as the core device, not afraid of contact ignition and oxidation. Double-parallel connection, independent channels, current multiplication, and internal resistance are reduced by half at the same time, which is beneficial to lossless transmission of sound 3:Using 7812 as voltage regulator, the power supply range is wide, up to any range from AC12V to AC15V 4: Two channel split Mirror design. Convenient and practical. Note: this list just for the Speaker protection kit/board. not include the Speaker terminals!!! NOTE: We have DIY kit or Finished board (Optional) ◆ DIY kit ---- All parts need you to solder and test it. ◆ Finished board ---- All parts have been welded and tested OK. Please refer to the following back panel for installation location: The following is our built well amp photos. it just for reference only !!!