Sensor fit
The Omron E3Z-D81K is an active-production retro-reflective photoelectric sensor using an 860 nm infrared LED, rated for a 5 to 100 mm wide-view detection range. It comes pre-wired with a 2 m cable and draws 30 mA max from the supply.
How it compares to nearby order codes
The E3Z-D61K uses the same IR LED but is diffuse reflective — it detects targets directly, not a reflector. If your application requires a reflector, the D81K is the correct choice. The E3Z-R81K is also retro-reflective but swaps the IR LED for a red 660 nm LED and has a longer nominal range. The D81K's wide 5–100 mm view is optimized for short-range area detection; which one fits depends on target distance and required spot size.