The Siemens 3RF3125-2AA24 is a SIRIUS 3RF31 solid-state relay, single-pole in a 22.5 mm housing, rated for 25 A continuous load current across 48-460 V AC, with a 110-230 V AC control voltage. Spring-loaded terminals speed wiring in the panel — no screw torque to verify, just strip and insert. That 25 A rating is the continuous resistive load; for motor or transformer inrush, the SSR's semiconductor junction handles the surge without derating the way an electromechanical contactor would, so it's a clean fit for cyclic or high-duty-cycle switching.
The 22.5 mm width matches the standard SIRIUS modular envelope — snaps onto 35 mm DIN rail and shares the same profile as the 3RF2 and 3RF3 contactor ranges, so panel layout and duct spacing carry over without rework. The 104 x 44 x 48 mm package leaves enough finger clearance for adjacent wiring ducts.
Group code R711 and product group 3725 are the internal Siemens classification tags — they matter for cross-referencing in the SIRIUS configurator or when ordering spare parts through the Siemens Industry Mall.