From Therm-O-Disc, this thermal cut-off switch is N/C (normally closed) by definition. (Thermal cut-offs are what keep your coffeepot from burning your house down.) This one shuts down between 221°F (105°C) and 248°F (120°C) and measures 5/8" dia x 9/16" thick, with (2) axial terminals.

It's a nonpolarized bimetal heat sensor, 1/2" long with rubber sleeves and 6" long leads. It's also mysterious, because when used as a thermocouple multimeter input, it reads approx 94° in nearly boiling water but approx 170° in ambient air. Wethinks some sort of inversion or scaling is going on, but a person with your smarts will surely figure it out.

To heat what is anybody's guess, but it's a U-shaped heating element, 8-3/8" x 2-5/8" x 1/4" dia with a 107 Ohm Resistance and rubber grommets above the 3/16" wide power terminals. When CJ heated it up to 120F, those grommets got gooey, so he says use lower voltage DC.

This dipped, nominally 10K Ohm thermistor is on a heatshrunk and tubed 27” lead with a 6mm 2-pin Molex connector. Resistance drops as heat increases (NTC). Comes encased in a 1” x 1-1/8” plastic housing with a clip. AC takeout.