The ABB XT1HU3015AYD000XXX is a NEXT1H 125 TMF 15-500 3P F F UL/CSA circuit breaker — a three-pole unit with a TMF (thermal-magnetic fixed) trip unit, rated for UL/CSA applications. The TMF trip block gives you a fixed thermal curve and a fixed magnetic pickup, so it's a straight swap-in for a panel that's already been coordinated. No adjustment knobs to fiddle with on the line.
The is current — ABB hasn't flagged this for phase-out. If you're stocking spares for a line that runs this breaker, the supply channel is the standard distribution route, not the surplus market.