This #1 selling heater is C.U.L approved for safety and is ideal for application in reptile, amphibian, small animal, or plant terrariums. This compact powerhouse uses a solid state nichrome element that costs only pennies a day to operate, and is an optimal 24 hour primary or secondary heat source for your tropical or temperate species. Kill the chill with the Repti Therm UTH, and ensure comfortable living for all your terrarium inhabitants.