The Omron E3T-ST14 is a through-beam photoelectric sensor set (transmitter and receiver) in the E3T series, delivering a PNP dark-on output at 12–24V DC over a 1m sensing range. Rated IP67 with a PBT body, it wipes up the small space with its 7 mm × 10 mm × 25 mm rectangular body and right-angle sensor face. Response time is 1 msec, minimum detectable object is a 2 mm diameter opaque target, and the 2 m prewired cable terminates in bare wires.
There is also a light-on variant of the NPN version (E3T-ST11) and a more compact through-beam (E3T-FT14) with 500 mm range — but those change either output logic or physical fit. For a same-footprint swap keeping the PNP dark-on logic, the ST14 is the only match.