Opteka EW-73B Lens Hood for Canon EF-S 17-85mm f/4-5.6 IS USM & 18-135mm f/3.5-5.6 IS Lenses Replacement for Canon EW-73B Lens Hood Compatible with the Canon EF 16-35mm f/2.8L, EF 17-35mm f/2.8L, & EF 17-40mm f/4L Lenses Prevent unwanted stray light from entering the lens Extra protection from accidental impact Designed to match the specific focal length of the lens