An inductive proximity switch used for position sensing in Wedeco ultraviolet plant — typically to confirm that a wiper or valve has reached its commanded position. This part is a Pepperl+Fuchs NBB5-18GM50-E0-V1, an instrument sold under its own manufacturer's designation, so it can be identified and specified generically as well as ordered here. The designation encodes the sensing range and the 18 mm barrel thread; confirm both against the existing switch before fitting. Wedeco was founded in Herford, Germany in 1976 and is now a Xylem brand.