What it is and what it does
The Omron E3S-2LE4 is a through-beam photoelectric sensor emitter only. It sends a light beam across a 2 m gap; the paired receiver detects the interruption. Operating on 12 … 24 V DC with a pre-wired cable, it fits inside -25 … 55 °C environments. This is the emitter half — verify you have the corresponding receiver before specifying.
What the ratings mean in practice
The 2 m sensing range is clean and reliable for moderate detection gaps — typical for box presence, pallet positioning, or part passage on a conveyor. The sensor operates on 12 … 24 V DC, so it will run off a standard control-voltage supply. The cable connection (no quick-disconnect) means replacement involves pulling new wire or splicing; plan for that during downtime.