Thermostat, thermal cut out. F113-20 NO.
Therm-O-Disc 36TX22 13115 F113-20
Thermostat, thermal cut out. F113-20 NO, self resetting. The 36T series of 1/2 inch 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/