This is a Genuine Manufacturer Sourced replacement part used on a Broan Heater. This part is made out of Metal and it is Sold Individually.

The purpose of it is, if the unit overheats, the Thermoprotector trips to cut off voltage to the the Heater. To determine if the thermoprotector is at fault, use a multimeter to test it for continuity. If the Thermoprotector does not have continuity, and it cannot be reset, replace it. The most common reasons for replacing a Thermoprotector are when your unit won’t heat or runs for a few seconds and then stops.