I designed this bracket to hold two aquarium heaters, which live in the bottom of the sump under my 125 gallon aquarium. The suction cup holders that came with the heaters had become brittle, and they don't stick very well to the bottom of the sump anyway, once it gets a layer of gunk on it. I've made this customizable mainly for the heater diameter, but there are a few other things to play with as well.