These devices rely on a specially formed bimetal “disc” to provide the work force necessary to open and close a set of electrical contacts.  The bimetal disc reacts to changes in temperature in an application and will provide the work energy to open and close the contacts.  Since the bimetallic element does not carry the circuit current of the application, these devices are not subject to the self-heating effect caused by the electrical load passing through the bimetal element.  This gives disc type devices the ability to handle higher current loads.

Models KO,
Automatic Reset - 1/2" disc thermostats with automatic reset at preset temperature. more...
Models KB
& CB
Manual Reset - 1/2" disc thermostats with manually activated reset. more...