What this 4-pole B-curve MCB does in the panel
At 25 A per pole, it handles a 400 V three-phase feeder or a 230/400 V split-phase subfeed in a residential or light-commercial distribution board.
DIN-rail fit and panel integration
The 72 mm width (4 MW) occupies four 18 mm module spaces; plan your enclosure fill accordingly.
How it compares to the 3-pole C-curve sibling
The closest functional peer in the same SENTRON family is the 5SL4363-7 — a 3-pole, C-curve, 10 kA unit. The 5SL6425-6 is 4-pole and B-curve, so it won't drop into a panel wired for 5SL4363-7 without rewiring the neutral leg and checking the trip coordination. The 6 kA vs 10 kA breaking capacity means this unit is suited for lower fault-current installations; if your panel's prospective short-circuit current exceeds 6 kA, step up to the 10 kA sibling or a higher-rated SENTRON variant.