The Canon ET-63 Bayonet Lens Hood is compatible with the Fits EF-S 55-250mm, f/4-5.6 IS STM Lens.

Lens hoods are primarily designed to prevent unwanted stray light from entering the lens by extending and shading the end of the lens. A dedicated lens hood is designed to match the angle of view of the lens it was designed for. Since the end of the lens is extended while the hood is in use, additional protection from accidental impacts to the lens’s front element is provided as well.