For a 25 A feeder protecting a motor control centre or a lighting distribution board, that dual-response is what keeps nuisance tripping low while still clearing a hard fault fast.
Mounting and integration into a panel
Mounts on a backplate in either horizontal or vertical orientation, flat on the back. The 108 mm width and 137 mm height fit a standard 12-module pitch at 9 mm per module — so it occupies the same footprint as a 12-module DIN-rail device, but it's a backplate-mount breaker, not a snap-on DIN unit. Front connections top and bottom simplify busbar and cable routing inside the enclosure. Terminals are Everlink lugs accepting 2.5 to 95 mm² rigid or stranded aluminium/copper, or 2.5 to 70 mm² flexible copper. That's a wide wire range — you can land a 70 mm² feeder on a 25 A breaker without a reducer, which is handy when the same panel has larger breakers sharing a busbar.
If your panel runs hotter, you'll need to derate — the thermal trip element responds to ambient temperature.