We use one of those for our rabbit. It doesn't get very hot at all but works to keep her warm when it gets frosty out. I second this suggestion.
So in a snake enclosure, it might well be the perfect amount of warmth where it's needed- instead of trying to push heat in from "outside" & underneath a thick cage bottom with typical UTH.
Rudeness is the weak man's imitation of strength. Eric Hoffer(1902 - 1983)
“The greatness of a nation and its moral progress can be judged by the way its animals are treated.” ~ Gandhi