The Schneider Electric A9F08406 is an Acti9 iC60H miniature circuit breaker with a D tripping curve, rated 6 A, 4 poles, and a breaking capacity of 42 kA Icu at 12-133 V AC. The D curve means the magnetic trip is set at 12 x In +/- 20 %, so it handles high inrush currents from motor or transformer loads without nuisance tripping — that's the main reason you'd pick this over a B or C curve in the same iC60 family.
The 4-pole unit occupies 8 x 9 mm pitches (72 mm wide). Terminals accept 1-25 mm² rigid or 1-16 mm² flexible wire; strip length is 14 mm.
Tropicalisation class 2 per IEC 60068-1 means it withstands 95 % relative humidity at 55 °C. The thermal-magnetic trip unit delivers 10,000 electrical cycles and 20,000 mechanical cycles. Isolation suitability is confirmed per both standards, and a contact position indicator is built in.