The Siemens 3RF3125-1AA22 is a SIRIUS 3RF31 solid-state relay, one-pole, in the standard 22.5 mm DIN-rail housing. It switches loads up to 25 A across a dual control-voltage range — 24–230 V AC and 110–230 V AC — and terminates via screw terminals. That 22.5 mm width is the narrow footprint that fits a dense panel; the 25 A rating means it handles moderate resistive or inductive loads without needing a heatsink in most panel environments.
RoHS compliant since 2024-01-15. No UL or CSA listing appears in the available data, but the part carries standard CE marking as a Siemens industrial product.