Sourcing & Compatibility
The E3Z-R81K is Omron's current-production retro-reflective photoelectric sensor — lifecycled as 'current', no obsolescence or last-time-buy in sight. That's one less SKU to worry about for long-term BOMs. This unit uses the same Red LED (660 nm) light source, same M.S.R. function for shiny targets, and same pre-wired connection as the E3Z-R61K. The only difference the listing carries is cable length: R61K states 2 m, R81K leaves it unstated but shares the same body and mounting. For a panel already wired with flying leads, this drops in without rewiring. If you need a connector rather than a pigtail, the E3Z-R61K-M3J gives you a 0.3 m cable with an M8 4-pin connector — same sensing core, different termination.
The 3 m sensing distance is the range to the reflector (150 mm dead zone at the lens). The M.S.R. function suppresses false signals from shiny backgrounds — relevant if you're sensing glossy packages or metal cans on a conveyor.