Repti Therm U.T.H. heaters are extremely economical to use and are U.L./C.U.L. approved for safety. They have a solid state nichrome heating element which uses only 16 watts of electricity and costs only pennies a day to operate. The heater permanently adheres to your terrarium, forming a solid bond for better heat transfer. Size: 12" L x 8" W Made for 30 - 40 Gallon Terrarium.