The C-curve means it holds through mild inrush (5–10× rated current) and trips fast on hard shorts, so it's the standard choice for mixed resistive-inductive loads where you don't want nuisance trips from transformer or motor starts.
At 54 mm wide (3 modular width units), it occupies three standard 18 mm DIN-rail slots — a common footprint for 3-pole MCBs in a Siemens SENTRON sub-distribution board. The 76 mm depth plus 70 mm installation depth means it clears most enclosure backplates without forcing a deeper can. Mounting position is unrestricted, so you can orient it vertically or horizontally in a tight gland-plate layout. If your fault loop impedance at the board is higher than 0.067 Ω (400 V / 6 kA), this breaker clears the fault within its rated limit. For industrial panels with higher prospective fault current, you'd step up to the 10 kA variant (5SL4363-7). Power loss is 2.3 W per pole in hot operating state at rated current — 6.9 W total for the 3-pole assembly. That's low enough to ignore derating in a standard 12-module enclosure, but worth checking if you're packing 24+ breakers in a sealed box. Rated for overvoltage category III (distribution board level) and pollution degree 2 (non-conductive dust, occasional condensation).