Cat. No. AA115LPK is a Alarm Signal lockout switch(AL/LO aux SW) auxiliary contact switch #1494D37G02 used in Cutler-Hammer ND-frame 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.