What this MCB is for
It's rated to clear faults up to 10 kA under EN 60898 and 15 kA under IEC 60947-2, so it handles industrial-grade short circuits in a 400 V AC circuit. That's a single pole slot in a distribution board — useful for packing branch protection into tight panels. Mounts in any position, which helps when you're retrofitting into a crowded enclosure.
The D-curve allows 10 times rated current for a short window. That is what you need for a motor branch circuit or a control transformer primary. The 15 kA rating per IEC 60947-2 gives headroom for higher available fault current — say, a panel close to a large transformer. Rated for 400 V AC and 60 V DC. The DC rating matters for control circuits or battery-backed loads.
If you're sourcing for a line-down situation, the 18 mm width and DIN-rail clip mean it swaps directly into any panel already using a 1-pole 5SJ4 or 5SL6 series MCB. No rewiring of the busbar or re-termination of the load side — same footprint, same tunnel terminals.