The Schneider Electric A9KF71306BQ is an Acti9 K60 miniature circuit breaker (MCB) with a C-curve trip characteristic, rated 6 A, 3-pole, for AC networks at 50/60 Hz. This is a thermal-magnetic MCB, so the bimetal handles sustained overloads and the solenoid clears short-circuits. It's rated for isolation per EN/IEC 60898-1, so you can safely use it as a disconnecting means for downstream circuits during maintenance — provided the load side is de-energized first.
The 54 mm width occupies 6 module pitches at 9 mm each on the rail, so a 12-way distribution board takes two of these before you add the RCDs and busbars. Depth is 70 mm, height 81 mm, which fits most domestic and light commercial enclosures with a 100 mm minimum internal depth. Tunnel terminals accept 1 to 25 mm² rigid or 1 to 16 mm² flexible; strip 14 mm and torque to 2 N·m top and bottom. Pollution degree 2 covers normal industrial atmospheres with only non-conductive contamination.