Penn Plax is a name that stands for Quality Innovation and Integrity In the Pet Industry for over 50 years Experience a great line of Pet Products in all categories! Penn-Plax is committed to creating and manufacturing innovative pet products for first-time pet owners and serious hobbyists alike. Category: Aquarium Decorations. Sub Category: Backgrounds. Cubes: 0.0072. Weight: 3.9200. Dimensions: 19-1/4 x 50.