The 3RG7640-3AA00 is a SIMATIC PXO210 M18S diffuse photoelectric sensor with energetic straight optics in an M18x65 barrel. It runs on 10-30V DC, switches PNP dark-on at 500mm range, and terminates through an M12 4-pole connector. Rated IP67, it's built for wet washdown zones on packaging lines or conveyor sorters.
The 500mm sensing range is rated for a standard white test card. PNP dark-on output goes high when the target is absent. The 150mA load capacity handles most PLC inputs or small relays directly.