Jackson Research safety interlock switches are used to detect the opening of guards - including doors, gates and removable covers - that prevent access to dangerous parts of a machine, and to help deter tampering with the guards or the internal machine controls.

The switch is magnetically actuated to the ON state when the magnet is in close proximity to the switch. Access to the machine moves the permanent magnet away from the switch turning the switch to the OFF state causing the machine to automatically shut down.