Leica Lens Hood Summarit-S 70mm ASPH.
This 12401 Leica Lens Hood is for use with the Leica Summarit-S 70mm f/2.5 Asph.(CS) Lens. Lens hoods are primarily designed to prevent unwanted stray light from entering the lens by extending and shading the end of the lens. In addition, since the end of the lens is extended, you also get the added benefit of some extra protection from accidental impact.