The 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.
Canon ET-63 Features
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