Big Apple Pet Supply Intellitemp Reptile/Amphibian Heat Mat 13.8" x 7.9" (20 Watts) Permanently sealed into a 1/8" thick heavy duty plastic shield creating a waterproof design Plastic shield that is not only incredibly durable but it is water and rot resistant Easily Mounted on the inside of the enclosure for optimal efficiency or under the enclosure for your convenience Produces rays just like the sun, heat is absorbed by the reptile just as though they were basking in a natural environment Automatically creates a range of temperatures that many species of reptiles and amphibians will utilize