UltraHeat brand of products has been the North American RV Industry's Standard for holding tank and drainage system freeze-up protection since 1991. The Peel-n-stick application, makes it easy to install. One powered "on", all tank heaters are sensor controlled to power cycle. Activating when tank contents drop to approximately 44 degrees Fahrenheit, and deactivates once heated to 64 degrees Fahrenheit. Sizes to fit all motorhome and trailer holding tank applications.