Supplied complete with pre-wired LEDs Simulating the white flash of arc welding. Arc Welding flash effects with a random pause feature. Adds character to any manufacturing facility or machine shop in your layout. Great for inside of factory buildings, garages, under cars, construction scenes, trackside welding etc. Its also a great way of attracting attention to your display. The arc welding effects board consists of two totally different flash outputs, each producing an arc welding flash. Supplied with one white high brightness LED and one blue, and pre-wired resistors for 12 volt operation. There is also a further resistor supplied, which could be used used to dim the effect of the blue LED, to give the display a more life like flash colour. The effect of using the blue and a white LEDs with out doubt improves the flash effect the unit produces. The effects controller is 34mm x 21mm and will fit in most small buildings or can mount it under the layout. You can also run wires from the circuit board to the LEDs and place it almost anywhere you want to. Perfect for all model railway scales or for use in displays. This product was designed by us and is still currently manufactored by us. We are therefore able to offer full technical telephone/email support if required.