The Festo SOEG-RSP-Q20-PP-S-2L-TI is a retro-reflective photoelectric sensor, meaning it detects objects by sensing the interruption of a light beam reflected back from a separate reflector. This is a common setup for presence detection on conveyors, packaging lines, and material handling stations where you need a reliable break-beam check without running wiring to the far side. Out here in the grease, retro-reflective is a solid choice — one device to mount and aim, no emitter-receiver pair to align.
The lifecycle stage is listed as current, so Festo is still building this order code.