It breaks fault currents up to 3 kA per both EN 60898 and IEC 60947-2 at 240 V AC, 50 Hz. That's a good fit for resistive loads like lighting strings, heating elements, or general-purpose socket circuits where inrush is low. For motor or transformer feeders with higher inrush, a C or D curve would be the better call; this one will nuisance-trip on a pump start.
The 5SQ2560-0KA20 occupies 2 width units (about 36 mm) on a DIN rail and installs at 55 mm depth — shallow enough for a 100 mm deep enclosure with room for gland plates and wiring gutters. IP20 finger-safe terminals are standard for enclosed panel gear; no washdown rating here, so it stays inside the cabinet. That saves a terminal slot and keeps the wiring tidy in a single-phase sub-feed.
This part carries a current lifecycle stage from the manufacturer — no phase-out notice on record. That means it's still a standard catalog line, not a last-time-buy scavenger hunt.