For a 63 A domestic or light-commercial distribution board, that's adequate for most utility-side fault levels; if your site's prospective short-circuit current exceeds 4.5 kA, you'd step up to a higher-rated MCB or an upstream backup fuse.
Clip-on mounting to standard 35 mm DIN rail (EN 60715). The 2-pole body occupies 4 module pitches at 9 mm each — 36 mm total rail width. Toggle control, grey housing. Compatible with comb busbars and distribution blocks per the manufacturer's listing, so you can feed a row of these from a single incoming supply without daisy-chaining wire.
This order code is marked Obsolete by the manufacturer. If you're freezing a new design, the Domae range has been superseded by later Schneider MCB families (Acti9, Resi9); check the form-factor and busbar pitch before substituting, since the module width and comb compatibility may differ.