This is a Brand New York/Luxaire/Coleman 3" Main Limit Switch rated at 175 Degrees (L175F-30) . The Part number is 2702-316P (OEM Replacement for Part #s listed below) . Thanks for looking and good luck!
A limit switch is a safety device designed to shut down a piece of equipment. Limits have a set point, which is in some cases, adjustable. The set point prevents the temperature or pressure from exceeding the rating of the switch.