When standard thermostats fail, they lock in the closed position and prevent coolant flow to the engine, which can potentially cause serious damage to your engine.
In the case of MotoRad thermostats with a patented fail-safe mechanism, a unique extra stoke enables operation in two stages:

Stage 1
Under normal operating temperatures, the fail-safe thermostat operates in the same manner as any other thermostat.

Stage 2
When overheating is caused by a deteriorating cooling system part, the fail-safe has a secondary stroke that activates a precision engineered piston. This automatically locks the valve into a wide open position to allow coolant to circulate freely.

Note that once the fail-safe thermostat has locked in the open position, it cannot be used again and must be replaced.