With a twist of a knob, you can adjust the temperature of most heating devices with the Repti-Temp Rheostat. Plug in up to two compatible heat sources with a combined wattage of up to 150 watts! Turn your heaters up or down depending on the ambient room temperature. Great for use with Zoo Med's Repticare Rock Heaters, Ceramic Heat Emitters, Reptitherm Under Tank Heaters, and Repti Basking Spot Lamps.