The Schneider Electric A9N21022 is a Prodis DT40 miniature circuit breaker rated 4 A with a C-curve trip characteristic (magnetic trip between 5 and 10 times In). The breaking capacity is 4.5 kA Icn at 230 V AC per EN/IEC 60898-1, and 6 kA Icu at 230–240 V AC per IEC 60947-2, so it covers both domestic-distribution and light-industrial panel applications.
The tunnel-type terminals accept 0.33–10 mm² flexible or 0.75–16 mm² rigid wire; strip length is 13 mm, tighten to 2 N·m. IP20 finger-safe terminals mean it's suited for enclosed distribution boards or control panels where incidental contact is prevented by the enclosure.
Rated for 50 Hz networks, pollution degree 3, overvoltage category IV, and tropicalised per IEC 60068-1 (class 2). Electrical and mechanical durability are both 20,000 cycles. The toggle gives local ON/OFF indication. Separate earth-leakage protection block can be added alongside.