The Siemens 3RG7407-7CH00 is a SIMATIC PXO320 L20 laser retro reflective sensor with a polarisation filter. It's rated for DC 10-30V supply, sensing range 5-300 cm, PNP output, and IP67 enclosure. The 31x20x12 mm housing uses an M8 4-pole connector.
The sensor is a retro reflective type with a polarisation filter, which helps reject false triggers from shiny targets. Output is PNP, and the light/dark-on mode is programmable — useful for adapting to different target presence logic. The 100 mA load capacity covers direct connection to most PLC inputs or small relays.