My old low voltage halogen bulbs were inefficient, heavy and hot! These new replacement parts are brighter, cooler and more efficient. Unlike other LED lights that perform a similar function, they had a built-in power supply and control box. Plastic yes, but fully functional. The only item you need to provide is a wire clamp/strain relief device to keep the Romex under control. Each light comes with wire nuts, but they only accept one #14 wire plus the wire from the LED light itself. Usually this type of light is wired in parallel with many others, as I have done. As a result, you should screw two Romex 14/2 wires to each LED wire. You must supply larger wire nuts.