The Lens Shade for 35mm f/1.4 Z Series Lenses from ZEISS is a dedicated lens hood designed to match the specific focal length of these ZEISS lenses. Lens shades / hoods are primarily designed to prevent unwanted stray light from entering the lens by extending and shading the end of it. In addition, since the end of the lens is extended, you also get the added benefit of some extra protection from accidental impact.