Lucite encased display of MICROTEMP Thermal Cutoffs, which are a type of thermal fuse manufactured by Therm-O-Disc. These devices are used as a safety component to protect appliances and electronic devices from overheating. A thermal cutoff is an electrical safety device that interrupts the flow of current when it reaches a specific temperature. They are a "one-shot" device, meaning they are non-resettable and must be replaced once they have opened the circuit. The display shows a complete thermal cutoff, a cross-section of the device, and its internal components, including the spring and thermal pellet. These fuses are widely used in a variety of applications, such as home appliances, industrial equipment, transformers, and motors. Great item for someone who works for or with Thermodisc as a display item or desk paperweight. Will ship USPS with tracking to winning buyer