These chrome-plated metal buttons are rugged and look real good while doing it! Simply drill a 16mm hole into any material up to 1/2" thick and you can fit these in place, there's even a rubber gasket to keep water out of the enclosure. On the front of the button is a flat metal actuator, surrounded by a blue plastic LED ring. On the back there are 3 contacts for the button (common, normally-open and normally-closed) and 2 for the blue LED ring (+ and -). Connect 3 to 6V to the LED to have it light up nicely, there's a built in resistor! If you want to use this with a higher voltage, say 12V or 24V, simply add a 470 ohm resistor in series with the LED connection to keep the LED current at around 20mA.