Underwater Treasures brings you this breathtaking assortment of 3D Aquarium Backgrounds. Add natural beauty to your aquarium with any of these incredibly realistic decorations. Featuring a tough and durable design, these backgrounds are great for both freshwater and saltwater applications. Made with non-toxic polyurethane foam (PU), Underwater Treasures 3D Backgrounds will not affect the pH of your aquarium. Installs easily with standard aquarium silicone (sold separately). Create a naturalistic aquatic environment for your fish! Also great for terrestrial, aquatic, and semi-aquatic terrariums. 24" x 18" (Background can be cut to fit custom applications).