The Siemens 3RF3320-1AA24 is a 1-pole solid-state contactor from the SIRIUS 3RF33 family, rated for AC-1 resistive loads at 20 A when the ambient is 40 °C. The control supply range is 110-230 V AC, and the main circuit handles 48-460 V AC. Screw terminals keep wiring straightforward for panel builders.
The 105 x 27 x 122 mm package leaves room for adjacent devices on the same rail — no special air gap needed for heat sinks at the 20 A rating, but derate above 40 °C if the panel runs hot. No moving contacts means it's silent and bounce-free, which matters for frequent cycling on resistive loads.