The A9F04120 is a 1-pole 20 A C-curve miniature circuit breaker from the Schneider Electric Acti9 iC60 series, designed for distribution boards and control panels on DIN rail. Breaking capacity is the headline: 36 kA Icu at 12-60 V AC, 20 kA at 100-133 V, 10 kA at 220-240 V, and 15 kA at 12-60 V DC. The 6000 A Icn at 230 V under EN/IEC 60898-1 is the domestic-grade rating; the higher Icu figures under EN/IEC 60947-2 are what you use for industrial coordination studies. Dual-rated to EN/IEC 60947-2 (industrial) and EN/IEC 60898-1 (domestic), so it qualifies for both commercial DBs and industrial MCCs. The thermal-magnetic trip unit gives a time-delayed thermal response for overloads and an instantaneous magnetic response for shorts — no electronics to fail.
Width is 18 mm (2 x 9 mm pitches), height 91 mm, depth 78.5 mm — a standard 1-pole module that clips onto a 35 mm DIN rail. Strip length 14 mm. That terminal capacity handles paralleled feeds or daisy-chaining busbars without adapters. The toggle control and trip indicator give a clear visual of the contact position — useful for lockout/tagout verification without removing the cover.
Electrical durability is 10,000 cycles, mechanical 20,000 cycles — fine for a distribution breaker that sees occasional switching, not a contactor duty cycle. If your application cycles it daily under load, consider a contactor instead.