Canon ET-83D Lens Hood for Canon EF 100-400mm f/4.5-5.6L IS II USM Lens - Compatible
Lens Hoods are primarily designed to prevent unwanted stray light from entering the lens creating lens flare and improving contrast and image quality. A hood also extends the length of the lens, assisting with keeping debris, moisture and dust away from your precious glass and protecting your lens from accidental impact damage.