S7-300 has been superseded by the S7-1500, but it still runs a large share of the installed base in industrial plants, and spares demand has not gone away. We supply CPUs, digital and analogue signal modules, communication processors, front connectors, bus connectors and rack accessories for the S7-300 — new where still available, and sourced through our import network where it is not.
Siemens has phased out the S7-300 in favour of the S7-1500, so availability is now driven by remaining stock rather than fresh production.
The S7-1500 family is the successor, but it is not a drop-in swap: the rack, I/O and program all need migration work. For a broken machine, a like-for-like S7-300 spare is normally the faster route.