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 manufacturing, we custom form the wax pellets for different temperature range specifications. All units are calibrated and tested to confirm switch actuation at their specified temperature In production, all thermal switches are factory-calibrated to make electrical contact at the specified lower-temperature set point As a global manufacturer of original equipment ignition products, we maintain complete quality control throughout the manufacturing process from componentry to finished product Robust design and high grade materials meet the stringent demands of today's service professional 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 controllerPackage Dimensions: 2.0 x 1.5 x 3.5 inches Package Weight: 0.205 lb Package Quantity: 1 UPC: 091769032272 Attachment Method: Plug In Bulb Included: No Color/Finish: Gold Connector Gender: Male Connector Quantity: 1 Connector Shape: Round Hardware Included: No Housing Material: Metal Mounting Bracket(s) Included: No Open at Idle: Yes Overall Width: 22.098 MM Switch Actuation Style: Toggle Switch Shape: Round Terminal Gender: Male Terminal Quantity: 2 Terminal Type: Bullet Thread Size: 16MMX1.50 Voltage: 12 Width - Inches: 0.87 Wire Quantity: 0 Wiring Harness Included: No Country of Origin: JP