The dedicated Sony ALC-SH105 Lens Hood is specifically designed for use with the SAL-16105 AF DT 16-105mm f/3.5-5.6 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.
This dedicated lens hood is designed to match the specific focal length of the lens it was designed for.
Reviews Sony ALC-SH105 Lens Hood for 16-105mm f/3.5-5.6 Lens (Sony Malaysia)