Jancos Lens Hood for Canon EF 16-35mm f/2.8L, EF 17-35mm f/2.8L & EF 17-40mm f/4L Lenses (EW-83E) Replacement for Canon EW-83E Lens Hood. Prevent unwanted stray light from entering the lens. Extra protection from accidental impact. Designed to match the specific focal length of the lens. Drastically improves your image quality.