The Siemens SIRIUS 3RT2037-1NB34-3MA0 is an S2-frame power contactor rated for a 20-33 VDC coil with screw-type terminals. It mounts on 35 mm DIN rail per DIN EN 60715 and accepts +/-180° rotation on a vertical surface, plus +/-22.5° tilt forward/backward — handy when you're squeezing it into a tight panel and need to angle the wiring access.
The S2 frame size tells you the physical envelope and the contactor's current-handling class — it's the middle frame in the SIRIUS line, bigger than S0, smaller than S3. The 20-33 VDC coil range means it pulls in reliably at 20 V and holds through dips up to 33 V; inrush peak is 3 A, so your 24 VDC supply needs to handle that surge without droop. The coil's operating power is 2 VA at both 50 and 60 Hz, which is low enough that a standard PLC output can drive it through an interposing relay.
Where it goes in a panel
This contactor is built for motor switching in control panels — think conveyors, pumps, fans, compressors on 400 V three-phase lines. The screw-type coil terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire, so it plays nice with standard panel wiring. The physical footprint is 55 mm wide, 114 mm tall, 174 mm deep — that's about two standard MCB widths on the DIN rail, leaving room for overload relays and busbars in the same row.
This part is listed as current production. It is a standard BOM line item.