Zoo Meds Snake Strip Under Tank Heater fits 10 gallon & larger terrariums. Size: 3.5 x 18 Features: Perfect for snakes! Narrow strips are the preferred heater shape by snake keepers worldwide. Promotes Thermoregulation: Heats the rear portion of the habitat and creates the perfect thermal gradient! Efficient, Proven Design: Uses just 10 watts. Sticks directly to glass for optimum heat transfer.