What the listing tells you
It carries the part number 1SAZ721201R1035 straight from the ABB franchise line, which is what an integrator or MRO planner needs pinned on the purchase order and what the panel label will show after wiring.
Where this class lives in the panel
Solid state overload relays in this ABB series sit downstream of the contactor in a motor feeder, where they sense phase current and trip the contactor coil on sustained overload — that is the function the class is specified for, distinct from a short-circuit protective device upstream. Because the listing gives no current range, trip class, or control voltage, the panel builder has to confirm those four functional ratings against the specific motor and contactor combination before the part can be released to wiring.
Sourcing posture
No production-status entry, last-time-buy date, or official successor appears for 1SAZ721201R1035, so the listing is sourced to order against an RFQ through the ABB franchised line with traceability to the manufacturing lot.