It carries a 6 kA breaking capacity per EN 60898 at 230/400 V AC, which means it can safely interrupt fault currents up to 6,000 A — sufficient for most final sub-circuits in a building distribution board.
The D-curve trips instantaneously at 10 to 20 times the rated current (160–320 A for this 16 A unit). That delay above the C-curve threshold lets motor-starting or transformer-energizing currents pass without opening the circuit, while still clearing a hard short. The 6 kA breaking capacity (per EN 60898) is the standard rating for residential and light commercial distribution boards in most European markets; if your panel requires 10 kA or higher (per IEC 60947-2), step up to the 5SL4 series — same footprint, higher interrupt rating. Rated for single-phase operation up to 250 V AC and multi-phase up to 440 V AC, this 1-pole breaker fits a single phase leg in a 230/400 V TN or TT system. Depth is 76 mm, so it clears most shallow enclosures — check your gland plate clearance if the board is tight.