The 30 mA earth-leakage sensitivity covers personnel protection against indirect contact, and the 6 kA breaking capacity (Icn at 110...240 V AC, 50 Hz, per EN/IEC 61009-2-1) means it can safely clear a fault up to that level without welding its contacts shut — fine for most domestic and light commercial distribution boards where the prospective short-circuit current stays under 6 kA. The limitation class 3 rating (also per EN/IEC 61009-2-1) means it limits let-through energy well, which helps with downstream coordination.
The 73 mm depth keeps it inside standard 100 mm deep enclosures. Strip length is 15 mm. The IP20 rating covers the terminals (finger-safe); inside a modular enclosure it's IP40. The pollution degree 3 rating means it's suitable for environments with conductive or dry non-conductive pollution — typical of most distribution panels that aren't sealed clean-room gear.