What it is — and why it fits a spare cabinet
This is a Telemecanique XS630B3DBM12 inductive proximity sensor — the kind you tuck into the cabinet as a critical spare for a 36 VDC loop handling up to 200 mA. Rated for a 36 VDC supply, it switches the output at 200 mA, enough for a PLC input or small relay. Lifecycle is current, so you can order it without worrying about a last-time-buy clock running out.