This is the part you'd reach for when you need to switch motor loads or resistive heating in a control panel and the coil voltage is nailed at 220 V AC — common in European-style panels running off a phase-to-neutral or control transformer tap. It sits in the current lifecycle stage, meaning it's still a standard catalog item, not something you need to hunt as surplus.
The 3RT1036 sits in the middle of the SIRIUS contactor range — not the compact 3RT101 for light-duty switching, not the high-current 3RT105 for big motors. It's sized for applications where you need a standard 3-pole block with a 220 V AC coil, which is a common control voltage in many plants. If your panel runs on 24 V DC instead, you'd be looking at a different coil variant in the same mechanical footprint — the base contactor block is the same, just the coil changes.