The Omron EESX953R1M is a through-beam photomicrosensor from the EE-SX series, built for tight-space presence detection where you need a clean NPN signal at short range. Its 5 mm sensing distance means the emitter and receiver sit close together — typical for edge-of-tape, flag, or small-part detection on a pick-and-place head or conveyor rail. The 1 ms response keeps up with moderate-speed lines; if you're counting parts at 600+ per minute, that's your limit. Output is NPN, open-collector, rated for 50 mA — enough to drive a small relay or PLC input directly. Switching is selectable Light-ON or Dark-ON via the wiring, so you can flip the logic without swapping parts. Supply range is 4.5 to 26.4 VDC, which covers 5 V logic and 24 V industrial buses alike.
The package is compact: 13.5 mm wide, 12 mm tall, 11.7 mm deep. That footprint fits into a DIN-rail adapter bracket or a machined slot in a guard panel. The 1 m cable is pre-terminated — no connector to source, but you'll need to manage the cable exit in tight enclosures. IP50 means it's fine for dry, indoor use but not washdown; keep it out of coolant splash or dust-heavy areas.