The Omron E3JK-5M2 2M is a built-in power supply photoelectric sensor. This is a through-beam type sensor, meaning the emitter and receiver are separate units, and the sensing distance is determined by the beam path between them. The built-in power supply simplifies wiring — no separate external amplifier or controller is needed for the sensing function.
A close functional peer is the Omron E3Z-LT81, also a through-beam photoelectric sensor. The E3Z-LT81 operates on 12 to 24 VDC and has a 60 m sensing distance, with an open-collector output. The E3JK-5M2 2M uses a built-in power supply, which typically means it can accept a wider AC/DC input range and provides a relay or solid-state output without needing a separate power module. The E3Z series is more compact and designed for DC-only control circuits. The choice between them depends on the control voltage available in the panel and the output interface required by the PLC or relay logic.