This heated "safety stone" is designed as a secondary heat source for tropical reptiles. The insulated nichrome wire element runs continuously back and forth throughout the heater, creating an even heat source with no "hot spots." The element is water-resistant to prevent possible electric shock if heater gets wet. Washable surface prevents bacteria build-up. Features full coverage, completely encapsulated heating element. Standard and Giant feature Repti-Temp Control for accurate temperature adjustment. The Standard Rock Heater (10½"W x 7"D x 2"H) is ideal for all types of snakes and lizards including boas, pythons, rat snakes, king snakes, iguanas, monitors, and tegus. Easy to use, simply put the rock heather in the terrarium and plug it in. The heater takes approximately 2 to 3 hours to heat up and should feel warm to the touch. The rock surface heats to temperatures of between 90 to 110° F.