This is an Omron E2E-X5Y1-M1, an M18 shielded inductive proximity sensor from the E2E series. It is a 2-wire AC normally-open device rated for 20-264V AC supply with a 5 mm sensing distance on ferrous metals. The sensor is built in a 303 stainless steel body rated IP67 and NEMA 4X, making it suitable for cutting oil environments and washdown areas. An M12 connector and integrated cable protector simplify field replacement. Output load is rated 300 mA maximum; the output circuit itself is limited to 100 mA maximum and 5 mA minimum.
Comparison with E2E-X5Y1-M4
The closest same-sensing sibling is the E2E-X5Y1-M4. Both share the 5 mm shielded detection range, 2-wire AC output, and M18 stainless body. The difference is in the package: the M4 has a 43 mm overall height versus 53 mm on this M1, and the M4 uses a 4-pin M12 connector while the M1 uses a 2-wire M12. The pin count and depth mean they are not a direct mechanical swap. If your panel is dimensioned for the M4, measure the available clearance and check connector pinout before substituting the M1.