Lens hood offers several benefits to the photographer. Primarily the hood shades the lens from stray light that may result in an unwanted discoloration or hazing of the image, or the appearance of lens flare; shading your lens helps improve contrast and image quality. Also it offers limited protection from keeping moisture and wind blown debris off the from lens element and adds extra protection from accidental impact.
Designed for Tamron 24-70mm f/2.8 Di VC USD lens
Designed to prevent unwanted stray light from entering the lens
Ensures no problems with vignetting or motor functions
Added benefit of extra protection from accidental impact