Lens hoods are primarily designed to prevent unwanted stray light from entering the lens by extending and shading the end of the lens. In addition, since the end of the lens is extended, you also get the added benefit of some extra protection from accidental impact.
Compatible Canon Lenses:
Canon EF 50mm f/1.8 II Lens
Please Note:
Due to design, the lens hood is not reversible
All pictures are for illustration purposes only. Actual product may vary slightly due to ongoing improvements in design.