The MGN61811 is a Schneider Electric Multi9 C60H-DC miniature circuit breaker rated 63 A at 50 °C per EN/IEC 60947-2, with a B-curve magnetic trip at 5.5 x In ±20 % DC. That means it trips on moderate overloads and short circuits in DC circuits — common for telecom, solar combiner boxes, or battery-bank protection where you need fast clearing but not the instant reaction of a C curve. Single-pole, rated operational voltage up to 250 V DC, with a breaking capacity of 20 kA at 110 V DC and 10 kA at 220 V DC.
The 18 mm width per pole means a 1P breaker takes two 9 mm pitches — 18 mm total rail space. IP20 finger-safe terminals; IP40 in a modular enclosure. Tropicalisation per IEC 60068-2, pollution degree 3.