The Frigidaire 297216600 Refrigerator Defrost Thermostat is a model number that refers to a specific type of refrigerator. It may have a defrost thermostat, which is a type of thermostat that is designed to keep the interior of the refrigerator free from frost and ice buildup. https://www.hnkparts.com/297216600-frigidaire-defrost-thermostat