At 4 A, it protects downstream wiring and loads up to that continuous current. The 10 kA breaking capacity (both per EN 60898 and IEC 60947-2) tells you it can safely interrupt a fault current up to 10,000 A without welding or exploding — a standard rating for most residential and light commercial distribution boards.
The 76 mm depth plus 70 mm installation depth means it sits flush in a 4-module enclosure with room for wiring.
