Got a couple questions about these. I have seen them in a few cage builds and was wondering, where do I get them(cheapest supplier) and for mounting, can they be mounted directly to the inside of a plywood enclosure, and are they safe for the animal to come directly in contact with them? Would like to mount on in the upper part of the cage side at one end, or do they need to be fastened to the top? And if your wondering, no I don't really know anything about these, they just seem as if they would be a good solution to my heating needs. Also need some sources(brands and suppliers) for thermostats. Wiring is not an issue for me, just want the least expensive good quality units I can get.