What it is and where it goes
The E2E-X18MY1-M4: This is an OMRON E2E inductive proximity switch — unshielded head, 18 mm sensing distance, normally open output, wired AC 2-wire. Line voltage in, no DC supply needed. That 1/2-20 UNF microchange connector means you're not grabbing a standard M12 cordset; verify the mating plug before the panel shuts. Unshielded gives you longer range than a flush-mount shielded, but demands clear air around the face — no metal within the head diameter. Typical fit: presence detection on packaging conveyors, material handling, or machine tool position feedback where an AC load (contractor coil, relay) gets driven directly.