Siemens 3SE2120-1DV00-0AC4 is a metal-enclosed position switch with a roller plunger actuator and snap-action contacts. It provides a 1NO+1NC configuration in a 4-pole, fixed-mount housing and uses an M12 4-pin connection for wiring. The M12 pins are assigned so that pins 21 and 22 form the normally closed contact, and pins 13 and 14 form the normally open contact, for a four-wire connection; the unit is designed to pair with the matching coupling plug 3RX8000-0CB45. This device is built for robust, compact position sensing in industrial control circuits where reliable actuation from a roller plunger is required.
