to begin, this is for beginners. I myself am one. It is very simple. It is pretty much just a red LED and 2 AAA batteries. The batteries are inside a battery case. The battery case is on the bottom of the Altoids tin (not actually an Altoids tin, but something alot like it.) The LED sticks through a hole drilled through the side, and the cords from the battery case go into the Altoids tin through 2 tiny holes drilled in the side. There was a resistor already attatched to the LED. A simple button protrudes from the top, and heat shrink plastic is used to complete the circuit.