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 perfectly match the specific focal length of the  lens it was designed for. Moreover, this hood features a non-glare matte  finish on the interior surface, to further prevent or limit lens flare. And  since the end of the lens is extended, you also get the added benefit of  some extra protection from accidental impact. The bayonet mount is designed  to also work in the reversed position, allowing the hood to be placed  backwards over the lens for a more compact storage solution.

Compatible models:

JJC LH-J55B replaces OLYMPUS LH-55B Lens Hood

Olympus M.Zuiko Digital 12-50mm F/3.5-6.3 lens

Olympus M.Zuiko Digital ED 9-18mm F/4.0-5.6 lens