Thermostat, thermal cut out. NC.
Therm-O-Disc 36TX21 2311 L230-40F
Thermostat, thermal cut out. NC opens on temp increase.
1/2" (12.77mm) Bimetel Disc 3/16" blade terminals, one on each side.
The 36T series of 1/2'' bimetal thermostats from Therm-O-Disc® offers proven reliability in a compact, versatile, cost-effective design. The snap action of the bimetal disc provides high-speed contact separation resulting in excellent life cycle characteristics at electrical loads up to 15 amps at 120VAC and 10 amps at 250VAC.
Please see: http://electronicsurplusblog.com/replacing-thermal-cutout-devices-with-surplus-look-alikes/