This is a wiring enclosure for mounting Tekmar tn4 controls. It mounts on the wall and the controls snap into it. There are a large amount of 1/2" knockouts to facilitate wiring. One of the pictures shows two Tekmar tn4 modules mounted in the enclosure. THOSE MODULES ARE NOT INCLUDED. But you can find them in one of my other auctions. I frankly don't know if there is any need for this type of unit but I thought I would put it out there before I trash it.