The Schneider Electric A9N4P63BIN is an Acti9 xC60 miniature circuit breaker rated 63 A, 4-pole, with a B tripping curve.
The B curve means magnetic trip at 3–5× In — so 189–315 A instantaneous. That suits resistive and general-purpose loads (lighting, small motor circuits with low inrush) but not heavy inductive loads like large transformers or motor starters where a C or D curve would avoid nuisance trips. Four protected poles mean all four phases are switched and monitored — needed for three-phase plus neutral or for a 4-wire system where the neutral must be protected. Below that voltage the rating holds; at 220–250 V DC it drops to 6 kA Icu.
Width is 72 mm, which is 4 modules at 18 mm per pole; depth 77.5 mm leaves clearance for wiring behind the rail. The toggle control gives local ON/OFF indication.