In design, we specify custom wax formulations that will expand when heated, activate a snap action electrical contact and transfer the electrical signal to the fan controller. In manufacture, we custom form the wax pellets for different temperature range specifications. All units are calibrated & tested to confirm switch actuation at their specified temperature. The switch is designed using a formed bimetallic contact arm. The bimetal contact movement is achieved using the different expansion rates of two metals fused together. This is a creep action device, provides precise performance. In production, all thermal switches are factory-calibrated to make electrical contact at the specified lower-temperature set point. Our switches feature a robust design with high grade materials to meet the stringent demands of today's service professional. Standard is a global manufacturer of original equipment ignition products, complete quality control is maintained through the manufacturing process from componentry to finished product. Package Dimensions: 1.500 x 1.156 x 2.875 inches Package Weight: 0.03 lb Package Quantity: 1 UPC: 091769089269 Connector Gender: Male Terminal Quantity: 1 Terminal Type: Blade Country of Origin: US Remanufactured Part: N