The Schneider Electric MGN19744 is an Acti9 DCP Vigi residual current breaker with overcurrent protection (RCBO) — a 4-pole unit rated 16 A with 30 mA earth-leakage sensitivity, B-curve magnetic trip (3...5 x In), and a 6 kA breaking capacity at 380...415 V AC 50 Hz per EN/IEC 61009-2-1.
Ratings that matter for the install
The 30 mA earth-leakage threshold provides personal protection against direct contact, standard for residential and commercial final circuits. Thermal-magnetic trip technology gives you a bimetal element for overloads and a solenoid for shorts. The magnetic trip limit of 3...5 x In is the B-curve window — below 3 x In the thermal element handles it; above 5 x In the magnetic trip is guaranteed. That's a tight window for selectivity with downstream MCBs. If the board sees washdown or condensation, you'll need an IP65-rated enclosure around it.
Clip-on mounting on standard DIN rail, 8 x 9 mm pitches wide — that's 72 mm, so it takes up four standard 18 mm module widths. The toggle gives ON, OFF, and fault-trip indication, plus a contact-position indicator so you can see the state without pulling the cover.