It's the kind of part you'd find in motor control centers, pump panels, and conveyor line starters — anywhere you need to switch a three-phase load and a neutral or a second auxiliary circuit.
Four poles give you flexibility: three for the motor leads, one for a neutral or a control-circuit interlock. The 100-250V coil covers most common control voltages across North America and Europe — 110V, 120V, 208V, 230V, 240V — without swapping coils. Mount it on a DIN rail or a backplate; ABB's AF series shares the same footprint as the A-line, so retrofit into an existing panel is straightforward.