OMRON Photoelectric Sensors E3S series is Amplifier built-in photoelectric sensor.

OMRON Photoelectric Sensors E3S series models:

E3S-LS10XE4 2M    E3S-LS20XE4 2M    E3S-R2E4    E3S-DS10E4    E3S-DS30E4    E3S-R2E41    E3S-DS10E41    E3S-DS30E41

E3S-2E4 *
Emitter E3S-2LE4 *
Receiver E3S-2DE4 *

E3S-5E4 *
Emitter E3S-5LE4 *
Receiver E3S-5DE4 *

E3S-2E41 *
Emitter E3S-2LE41 *
Receiver E3S-2DE41 *

E3S-5E41 *
Emitter E3S-5LE41 *
Receiver E3S-5DE41 *

Model Summary
E3S-LS10XE4 2M: limited reflection type, detection distance: 30 ~ 100mm, when the light ON / shading ON switch, no contact output, wire leads (2m)
E3S-LS20XE4 2M: limited reflection type, detection distance: 50 ~ 250mm, when the light ON / shading ON switch, no contact output, wire leads (2m)