What the description tells a field tech
The XT4NE3250FFF000XXX: The description tags it as XT4N 250 Eki — that '250' is the frame size, so the breaker's physical footprint and bus-bar spacing match the XT4 family. If you're swapping one in a live panel, the mounting hole pattern and lug centers are the same as any other XT4N 250. No adapter plate needed, no re-drilling the backplate. The 'Eki' suffix points to the internal trip unit configuration; keep the same suffix if you're replacing like-for-like to avoid nuisance trips or coordination gaps.
