Omron E2E-S05S12-WC-B1 5M is a 5mm diameter threaded shielded inductive proximity switch, pre-wired with a 5-meter PVC cable. It gives you a PNP normally open open-collector output, sensing ferrous metals up to 1.2 mm away. That's a tight sensing gap, so it's meant for precise presence detection in small mechanisms—think cam lobes, actuator positions, or part-present on a pick-and-place gripper.
At 5 mm diameter and shielded, you can thread it into a standard 5 mm hole and mount it flush with the surrounding metal. The shield prevents the field from radiating sideways, so you won't get false triggers from adjacent metal. The threaded case gives you a positive stop; a jam nut locks it in place. Pre-wired with 5 m of PVC cable—that's enough to reach a terminal block inside a small panel without a junction box.