Under tank heater. Ideal for use with reptile, amphibians, small animal, or plant terrariums. Terrariums 10 to 20 gallons in size. One adhesive side "sticks" directly to the bottom or side of your terrarium for optimum heat transfer. Repti therm U.T.H heaters range from 5 to 25 watts making them extremely economical to operate. Laboratory tested and approved. Can be used with a thermostat and/or in conjunction with an additional heat source for higher temperature species Full one year warranty. Complete instructions enclosed.