The Omron E2B-S08KN04-MC-C2 is an unshielded M8 inductive proximity sensor with a 4 mm sensing range, NPN NC output, and a stainless steel barrel terminated in an M8 3-pin connector. Runs on 12 to 24 VDC—typical for industrial PLC inputs. The NC (normally closed) output means the signal drops when a target is present; confirm your logic expects that. Unshielded construction gives you a longer sensing distance (4 mm vs 2 mm on shielded M8 peers) but the sensing face needs a non-metallic surrounding to achieve that range—no flush mounting against steel.
How it compares to the shielded E2B-S08KS02-WP-C2 5M
The shielded E2B-S08KS02-WP-C2 5M is also M8 NPN NC, but it uses a PVC cable instead of the M8 connector and senses at only 2 mm flush-mountable.