Inductive proximity sensors, IQG, IQ40-40NNPKC0K, switching distance Sn: 40 mm, installation in metal: non-flush, cuboid shape (W x H x D): 40 mm x 40 mm x 66 mm, electrical design: DC 4-wire, switching output: NPN, switching function: antivalent, connection type: connector M12, 4-pin