The OMRON D4NL-1CFG-B is a Guard Lock Safety Door Switch from the D4NL Series. It is a compact, electromagnetic locking type safety interlock switch designed for hinged or sliding machine guards. This model features a 2 NC + 1 NO contact configuration for the door detection circuit (slow-action, direct opening mechanism on the NC contacts) and a separate 3 NC contact configuration for the solenoid lock monitoring circuit.