Lens hood is one of the most important accessories for each lens you own. A lens hood provides multiple functions: it shades the lens from stray light, improving your contrast and image quality; in inclement weather, it can assist in keeping moisture or wind-blown debris off the lens; and it protects the front barrel from the inevitable impacts against walls, door frames, and other real-life obstacles. Compatible with: CANON EF 135mm f/2L USM CANON EF 180mm f/3.5L Macro USM