This a new in box right hand normally open, one normally closed (1A-1B) 120V auxiliary contact switch, signal device used in Cutler-Hammer MC3800F frame circuit breakers. This switch is used to indicate circuit breaker status, and is used for remote signaling and system interlocking purposes. These switches are necessary in industry for reporting the operating status of machinery or equipment running. Without these signal type switches a person would have to manually walk to equipment and verify status. Instructions included. Sold as new surplus.