The 3RT2037-1SF30: Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715. The mounting position is flexible: +/-180° rotation on a vertical surface, and can tilt forward/backward by +/-22.5°. Clearance needs are tight — 10 mm upward, 10 mm forward, 10 mm downward, 6 mm at the side. That fits most standard enclosures without reworking the gland plate.
Rated for 800 switching cycles per hour at AC-1, 700/h at AC-3, and 200/h at AC-4. The arcing time runs 10 to 20 ms. Coil inrush peaks at 25 A, steady-state draw is 2 VA at 50 or 60 Hz. The MTBF is listed at 52 years — that's a reliability figure for continuous-duty applications, not a warranty.