The 3450RG Series consists of a temperature-sensitive bimetal disc, electrically isolated from the switch, which actuates the normally closed contacts. The contacts open when the surface or ambient temperatures increase to the operating snap point of the calibrated disc. Response to temperature changes is extremely rapid due to the inherently low mass of the disc and the small size of the product. These products are factory calibrated to the customer’s specification. They have gold alloy contacts for low voltage applications.