The C-curve holds through 5–10× rated current before instant tripping, so it's a common fit for mixed resistive-inductive loads in a distribution board. The EN figure is the standard for domestic/commercial MCBs; the higher IEC figure matters when the RCBO is installed in an industrial panel with higher prospective short-circuit current. The 15 kA rating gives headroom for most sub-distribution boards fed from a transformer under 630 kVA.
Sizing and derating — the temperature story
Up at 40 °C it's 5.7 A; at 50 °C it drops to 5.3 A; at 60 °C it's 5 A; and at 70 °C it's 4.7 A. If you're packing this RCBO into a warm enclosure — say a panel with drives or transformers nearby — you need to apply that derating curve. The 2-pole, 2-module-width body (36 mm wide, 72 mm deep, 85 mm tall) fits a standard DIN-rail distribution board, and the mounting position is any orientation, which helps with tight layouts.