The ZS71 is designed to provide continuous emergency stop along exposed areas of machinery and conveyors which present hazards to operators/maintenance personnel. Unlike E-stop pushbuttons, emergency-stop cable-pull systems can be actuated at any point along the "trip-wire." The unit features a positive-opening NC contact which is forced open when the trip-wire is pulled. This design also assures actuation if the operator falls into, leans on, or is pushed against the trip-wire. In addition, the switch is designed to operate if the trip wire is cut or goes slack. Their rugged metal housing, small size and watertight design (IP65) make them ideal for use in hostile environments where space is limited.