This is a BRAND NEW Universal 300 Degree (L300F) Manual Reset Limit Switch. It goes in many applicances, including furnaces and dryers. It will replace all limits rated at 300 degrees with a frame size of 36TX16 (5/8" insertion diameter and 7/8" from mounting hole center to center). Look at your limit switch and you should find the temperature rating of yours listed on the switch itself (It will be the first three digits after the "L" number). Thanks for looking and good luck!