Review on Retractable Elbow Recessed 4 Inch 1496P by Aquarium Lanter

Nothing stated in the description but it only works with the MR16 bulb. If you have a regular screw in a downlight housing, look for a 120V center socket to MR16 adapter. The instructions also say to bend/break the reflector that the mr16 bulb is inserted into. I haven't done this and it still works fine. Love the 60 degree tilt and the ability to turn the light on the way you want it. The light is very close to the dartboard, I can easily use this to focus the light directly on the center of my dartboard.