The Schneider Electric A9F03406 is an Acti9 iC60N miniature circuit breaker rated at 6 A with 4 protected poles and a B-curve trip characteristic. It's a current-production part, so no lifecycle concerns for a new BOM line. Breaking capacity runs 36 kA Icu at 12-133 V AC, 20 kA at 220-240 V, 10 kA at 380-415 V, and 6 kA at 440 V AC per EN/IEC 60947-2. The Icn per EN/IEC 60898-1 is 10 kA at 400 V. The B-curve magnetic trip is 4 x In ±20 %. That's a lighting or resistive-load curve — not for motor starting.
Snaps onto DIN rail, 72 mm wide (8 x 9 mm pitches), 91 mm tall, 78.5 mm deep. That depth is the body only — allow clearance for the toggle throw and outgoing cable bend in a shallow enclosure. Double terminals top and bottom accept 1-25 mm² rigid or 1-16 mm² flexible. The IP20 finger-safe front is standard for enclosed distribution boards; it's not rated for wet locations.
Dual-rated to EN/IEC 60947-2 (industrial) and EN/IEC 60898-1 (domestic/similar). Pollution degree 3, overvoltage category IV, suitability for isolation marked on the device. That's the standard for non-condensing high-humidity environments — fine for most indoor plant rooms but not for direct washdown.