PUBackground -30*55*5.5cm. The distinctive 3-D structure gives your aquarium a fascinating illusion of depth. These are made of a highly condensed polyurethane, coated with epoxy resin.This complex production process makes it particularly easy to cut the colour background to size whilst providing an extremely tough, colourfast surface. Easy to cut to size. easy assemble with Absolute fish tanks. Modular expansion possible. Suitable for the use with saltwater aquariums.