ET-63 Lens Hood from Canon prevents unwanted stray light from entering your EF-S 55-250mm, f/4-5.6 IS STM lens by extending beyond and shading its front element. Additionally, it offers some extra protection against impact. Shades the lens from stray light, improving your contrast and image quality. Helps to keep moisture or wind-blown debris off the lens in inclement weather. Protects the front barrel from the inevitable impacts against walls, door frames, and other real-life obstacles