The 2-pole construction matches the ungrounded positive and negative conductors typical in transformerless PV systems, so you get simultaneous disconnection of both poles when a fault or overcurrent event occurs.
DIN-rail fit and panel integration
That means the comb busbar pitch and accessory footprint (auxiliary contacts, shunt trips, alarm switches) carry over from the standard S800 range — no custom busbar or adapter needed when swapping in a PV-rated unit.
Listed as current production.