The Schneider Electric A9F53404 is a 4-pole miniature circuit breaker from the Acti9 iC60H series, rated 4 A with a B-curve trip characteristic. The B-curve magnetic trip operates at 4 x In (±20 %). Breaking capacity is the headline number here: 70 kA Icu at 415 V AC per IEC 60947-2, and 10 kA Icn at the same voltage per IEC 60898-1. The 10 kA Icn is the rating for residential-style applications under the domestic standard; the 70 kA Icu is the industrial rating that matters for commercial and industrial distribution boards.
Clip-on mounting to a standard DIN rail, 4-pole width at 9 mm per pole (8 pitches total, so 72 mm wide). Depth is 78.5 mm, height 85 mm. Terminals accept 1–25 mm² rigid or 1–16 mm² flexible copper, with a tightening torque of 2 N·m. Earth-leakage protection is handled by a separate block (not integrated), so if you need RCD functionality, you add a compatible Vigi iC60 module downstream. The breaker itself is padlockable for lockout/tagout procedures.
Dual-rated to EN/IEC 60898-1 and EN/IEC 60947-2, which means it can be used in both residential (60898) and industrial (60947) applications. Pollution degree 3, tropicalisation class 2 per IEC 60068-1, and limitation class 3 per 60898-1 for energy-limiting performance under short-circuit conditions.