The EW-83K Lens Hood is primarily designed to prevent unwanted stray light from entering the Canon 24mm f/1.4L II USM 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.
The “petal” shape of this lens hood maximizes the amount of hood coverage for the minimum amount of weight and hood area. This dedicated lens hood is designed to match the specific focal length of the Canon 24mm f/1.4L II USM lens.