Further information for TURCK 15756 NI20-K40SR-VN4X2 inductive sensor
Inductive sensor, operating voltage 10.65 VDC, rated switching distance 20 mm, non-flush, 2 cable entries (axial, radial), smooth tube, 40 mm diameter, plastic, ABS, DC 4-wire, 10...65 VDC, changeover contact, NPN output, terminal compartment