A Perfecto Glass canopy is excellent way to reduce evaporation and keep fish from jumping out of the aquarium in either salt or freshwater tanks. It also helps prolong the life of your light fixture by protecting it from moisture. For safety all glass edges are seamed. These canopies are the economical, yet stylish way to top off your aquarium. With a polypropylene hinge for easy access to your tank, as well as a plastic back strip that can be cut for heaters, filters, etc., these canopies provide versatile and long-lasting performance. Dimensions shown below are for glass only. Therubber hinge and back strip will ensure proper coverage when canopy is installed. Please choose your canopy based upon dimensions and aquarium capacity. Made to fitPerfecto Aquariums and standard aquarium sizes listed below. Available in: 16 in.(5 1/2 Gallons) Dimensions:15 5/16 x 5 7/8 20 in. (10 Gallons) Dimensions: 19 1/4 x 7 3/4 24 in.(15 Gallons/20H) Dimensions: 23 1/8 x 9 3/4 30 in. (29 Gallons/20L) Dimensions: 29 1/8 x 9 3/4 36 in. (30 Gallons/40H) Dimensions: 35 3/16" x 9 5/8 48 in. (55/60 Gallons) Dimensions: 23 x 9 5/8 (2 Pieces)