. Without explosion protection. Connection thread el.: 1/2" NPT / pneu.: 1/4" NPT Mechanic Limit Switches (MLS), 2 mechanical limit switches and 1 digital output. Not applicable for natural gas applications. Device plug M12 optionally orderable with -Z D57. Without option module. . Brief instructions English / German / Chinese. Standard / Fail-Safe - Depressurizing the actuator in case of failure of electrical auxiliary power (single acting only). Without Manometer block / Booster.