What it is and what it does
The Siemens 3RH1122-1AP00-0TK1-ZX95 is a SIRIUS auxiliary contactor in Size S00 — the smallest frame in the SIRIUS family, meant for control-circuit switching, not motor loads. It carries 2 instantaneous contacts (NO/NC configurable) and is rated for 10 A operating current in AC-12 duty at 24 V, which covers resistive and solid-state loads typical of PLC and relay logic outputs. The 10 A AC-12 rating at 24 V is the headline number for control-circuit fit; at 230 V AC-12 it's still good for 6 A, enough for most contactor coil and indicator lamp circuits.
Panel fit and mounting
Width is 45 mm, depth 72 mm, height 57.5 mm — standard S00 footprint that clips onto a DIN rail (snap-on) or accepts screws for panel mounting. The mounting position is flexible: ±180° rotation on a vertical surface, plus ±22.5° tilt forward/backward, so it fits tight enclosures without derating. Front protection is IP20 — fine inside a cabinet, not for washdown. Solid conductor terminations accept 2x 0.5–1.5 mm², 2x 0.75–2.5 mm², or 2x 4 mm², which covers most control wiring gauges without pigtails.