The Schneider Electric A9K23406 is a 4-pole miniature circuit-breaker from the Acti9 iK60N series, rated 6 A at 30 °C with a B-curve trip characteristic (magnetic tripping between 3 and 5 times In).
For most final sub-circuits in a TN or TT system this is adequate; if your point-of-supply SCCR is higher, you will need to step up to an industrial MCB or fuse. It will trip faster on a modest overload than a C-curve, which matters when you are coordinating downstream with a 6 A load that has no motor start. Four protected poles in a single 72 mm wide module (8 × 9 mm pitches) let you switch all phases and the neutral in a 3-phase + N distribution board. The thermal-magnetic trip unit covers both overload (thermal bimetal) and short-circuit (solenoid) protection on each pole.
Integration notes for the panel builder
The 72 mm width (4-pole) occupies eight 9 mm pitch positions on the rail — plan your enclosure fill factor accordingly. Storage temperature range of -40 to 85 °C covers most warehouse and transport conditions. The toggle gives a clear ON/OFF indication; no auxiliary contact position indicator is built in.