The ABB XT1HQ3015AFF000XXX is a 3-pole molded case circuit breaker from the XT1H series, built on a 125 A frame and fitted with a TMF 15-500 A thermal-magnetic fixed trip unit. The description confirms UL and CSA certification, so it's ready for North American panel builds where those listings are required.
The 125 A frame size tells you the physical envelope and maximum continuous current the breaker can handle; the TMF 15-500 A trip unit means the thermal-magnetic element is adjustable or fixed within that range, covering motor and feeder protection duties. The 3-pole configuration suits three-phase circuits, and the UL/CSA listing means it meets the short-circuit current rating (SCCR) requirements typical for North American industrial control panels.