The ABB XT1NQ3125AAA000XXX is a 3-pole molded case circuit breaker from the XT1N 125 frame, fitted with a TMF 125-1250 thermal-magnetic trip unit. The description on the nameplate reads XT1N 125 TMF 125-1250 3P F F UL/CSA — that tells you the frame size, the trip block, and that it carries UL and CSA marks.
The 125 A frame with a TMF 125-1250 trip means the breaker is adjustable over that range — you set the magnetic pickup to match your downstream load without swapping the whole unit. The UL/CSA listing tells you it's accepted in the US and Canada for branch-circuit protection.
