What the 5 mm sensing distance means on the line
The Omron E2E2-X5C1-M1 is a shielded M18 inductive proximity sensor with a 5 mm sensing distance on mild steel. The correction factor for stainless steel reduces the effective range.
PNP NO output and wiring
This sensor outputs PNP normally-open. That means the output switches high (to the supply voltage) when the target enters the sensing field. Three-wire DC: brown to +24 VDC, blue to 0 V, black as the switched output. The M18 barrel threads into a standard 18 mm mounting hole; the two nuts lock the axial position.