PCBA Size: 17mm*8mm Designed to save time, space and to help maintain a cleaner DCC installation. Intended for use with DCC Mobile, Sound and Lighting decoders requiring a hardwired installation with an output of 12V on the function common wire. Designed for use with most LED’s. Test your LEDs with a 12V power supply or a 9V battery with a 1K ohm 1/8 watt resistor wired inline on one of the leads prior to installation1. It contains eight 1K Ohm 1/8W SMD resistors for up to 8 lighting functions including headlight and reverse light. This compact board measures only 17mmX 8mm and is perfect for narrow hood diesel locomotives! Installation is a breeze... Simply solder the blue wire from the decoder to the " Blue Wire (+)" pad on the board and solder the wire to anode of each LED from the solder pads marked for each function (FL/RL/1/2/3/4/5/6) and then solder the appropriate wire from the decoder to the negative lead of the LED corresponding to that function!