The Cutler Hammer-Eaton C320KGS20 1 N/O Aux. A contactor serves as a critical auxiliary contact, enhancing the functionality and safety of HVAC systems. Specifically designed to work in conjunction with contactors, this component provides an additional normally open contact that responds to the status of the contactor. https://www.partshnc.com/c320kgs20-cutler-hammer-eaton-1-no-aux-for-contactor