What the description tells you
The XT4NU3225AYJ000XXX: The description breaks down as: NEXT4N series, 250 A frame size, TMF (thermal-magnetic fixed) trip unit with a rating of 225-2250 A (likely a typo or range for the trip unit adjustment; the 225 A setting is the one that governs the line-side protection), 3-pole, with front terminals (F F), and UL/CSA certified. The UL/CSA marking means it is accepted in North American installations without additional agency review.