What the 1.2 mm sensing distance means on the bench
The Omron E2EC04S12WCB12MOMS is a 4 mm diameter inductive proximity sensor with a flush-mount stainless steel barrel. Its 1.2 mm sensing distance is short — it detects ferrous targets only at near-contact range, so you're using this in precision position feedback or end-of-travel detection where the target passes within a millimeter. The 4 kHz switching frequency means it can keep up with fast-moving parts on a pick-and-place or a small cam indexer without missing pulses. Output is PNP normally-open, which is the standard sink for most PLC digital inputs in 24 VDC control systems.
The 4 mm barrel diameter lets this sensor fit into tight spaces — think M4 threaded holes or custom brackets in a gripper jaw or a small linear slide. Flush mounting means you can embed it in metal without worrying about false triggering from the surrounding material. The stainless steel housing and IP67 rating let it handle washdown on a food-packaging line or coolant splash on a machining center. The 2 m cable is pre-attached, so you run it straight to a terminal block or an M8 pigtail connector; no field wiring on the sensor itself.