The Exo Terra Rock Terrarium Background is an easy-to-cut background that has an incredible natural look. It creates a multi-dimensional habitat that is ideal for climbing reptiles or it can be simply used to beautify the natural look of the terrarium. Like all Exo Terra natural terrarium decorations, the color and texture of the Rock Terrarium Background has been chosen to create a perfectly harmonized environment, humid or dry. The deep ridges in the back are perfect to hide wires or tubing from pumps or Heat Wave Rocks. The background is made from black polystyrene, thus easily hiding scratches or claw marks from your reptile. Polystyrene has the advantage of providing insulation and is easy to cut to fit any size of terrarium. Inner Dimensions of the Box are 34 7/8 x 16 7/8 Inches.