Diffuse photoelectric — what the listing doesn't tell you
The Omron E3S-CD16 is a diffuse-mode photoelectric sensor from the E3S family, listed as current production. Diffuse means the emitter and receiver sit in the same housing, and the sensor triggers on light reflected back from the target — no separate reflector or receiver head needed. That simplifies mounting on conveyors or pallet-handling stations where you can't run a second cable or bracket.
What you need to confirm before the BOM line locks
The E3S-CD16 carries no published sensing distance, output type (NPN/PNP), or connection style in the spec record. That's the main sourcing risk: without the datasheet's rated range and output polarity, you can't confirm fit for a specific target material or PLC input card.