The Tough-Top Screen Cover is durably constructed from a corrosion free, galvanized woven welded steel wire with a prime virgin steel rim. The rim has a designer-black baked on textured polyester paint finish with a patented clear coating that provides superior scratch and corrosion resistance. The screen covers will withstand the high temperatures from most heating devices. The covers are available to fit standard 2.5, 5, 10, 15H/20, 20L/29, 30, 50, 55, 75, and 125 gallon aquariums.