The Siemens 3SE5112-0KD02 is a SIRIUS mechanical position switch with a roller plunger actuator — a positive-opening limit switch built to EN 50041 design C. The roller is high-grade steel, the housing is metal with cathodic dip coating, and the whole thing seals to IP66/IP67. That means it handles washdown environments and outdoor exposure without a secondary enclosure. Rated thermal current is 10 A, with switching capacities at 24 V (3 A), 240 V (6 A), and 400 V (0.12 A) — the 240 V figure is the one you'll most often see on a motor-control circuit. The contacts are slow-action with positive opening, so they meet the safety-circuit requirement for forcibly separating welded contacts.
Mounts in any position via screw fixing. The cable entry is a single M20 x 1.5 gland — standard for panel knockouts. Wiring is screw-type terminals accepting 1x (0.5–1.5 mm²) solid or 2x (0.5–0.75 mm²) solid, or AWG equivalents. Strip length and torque are per the terminal marking; the terminals are sized for the listed cross-sections, not for paralleling heavier loads. The supplied basic switch inside is 3SE5112-0KA00 — so if you ever need to replace just the switching element (not the head or housing), that's the sub-part number.