What this sensor is and what ratings matter for fit
The Omron E2E-C06N04-MC-B2 is a 6.5 mm diameter unshielded inductive proximity sensor from the E2E small-diameter series. It senses ferrous targets at 4 mm with a PNP normally closed output. The 3-pin M8 connector means you swap the cordset, not the cable. Because it is unshielded, you cannot press it flush into a steel bracket without losing repeatability — leave a non-ferrous gap at least the sensing distance from the face. For sourcing, the part is mature and available quoted to order; tell me the volume and I'll check the market pulse.
Mounting and wiring checklist
Mount the 6.5 mm barrel through a panel opening sized for the locknut, and for an unshielded sensor maintain a minimum radial air gap of 4 mm from steel surroundings. M8 cordset wiring: brown (L+), blue (L-), black (output PNP NC); tighten the locknut securely.