Inner-Tite Thermal Cut-offs are designed to disconnect power to heating systems when room temperature exceeds 165˚F (or 200˚F when optional 200˚F fuse is ordered). Cutting power to the heating system is a prudent way to aid in the protection of the heating system from further damage due to elevated room temperatures often caused by fires. Required by law in some states, Inner-Tite Thermal Cut-offs are economical, easy to install, and an effective back-up to existing built-in heating system controls.