The Exo Terra Heat Wave Rock simulates a stone heated by the sun (in nature, even after sunset, stones maintain some heat for several hours). Various reptiles, including nocturnal, use this form of conductive heat for thermoregulation which is important for metabolism and digestion. The Heat Wave Rock automatically shuts off when a certain surface temperature is reached to prevent burns or overheating. The fully-encased electronically controlled heating element covers the stone, prevent hot spots. The special thermal conductive resin is waterproof, non-toxic, easy to clean and ensures an even heat distribution. Natural looking Heat Wave Rocks are available in three sizes and are easy to integrate in any terrarium set-up; humid or dry.