On the panel
The E2E2-X5MC2-M1: This is an Omron E2E2-series long-barrel inductive prox in an M12 body. It runs NPN output, normally-closed, with a 5 mm unshielded sensing range. The nickel-plated brass housing takes a bracket or threads into an M12x1 hole, and the M12 4-pin connector makes it easy to swap without opening the panel — fix it where it sits.
Not a drop-in swap for E2E-X1R5C18-M1
If you're looking at the E2E NEXT series E2E-X1R5C18-M1 as a second source, stop — it won't drop in. That part is an M8 shielded body with a 2 mm sensing range and NO contact form, versus this M12 unshielded NC. Different mounting hole, different wiring logic. Stick with the E2E2-X5MC2-M1 for the original spec unless you're ready to re-engineer the bracket and the PLC input.
Mounting and hookup
Nickel-plated brass body, 70 mm overall, 48 mm threaded. Mount via bracket (12 mm hole) or M12x1 thread. Connect 12–24 VDC via M12 4-pin. Sensing distance 5 mm.