What it is — the key specs at a glance
The Omron E2K-X15MF1 is a 30 mm cylindrical capacitive proximity sensor from the E2K-X series, with a 15 mm sensing distance, PNP normally-open output, and 10-30 VDC supply. It is unshielded, preset at the factory — no sensitivity adjustment needed — and comes with a prewired 2 m bare-wire cable.
The E2K-X8ME1 is the same E2K-X series with an 18 mm diameter, NPN output, and 8 mm sensing range — both use a 2 m cable and 10-30 VDC. If your panel wiring expects a PNP input (sourcing), the E2K-X15MF1 drops in without rewiring the brown/blue/black leads; the NPN sibling would require swapping output polarity and typically a pull-up resistor. The longer 15 mm range also gives more tolerance for dielectric-constant variation in target materials.