The LH-49 Sliding Lens Hood from Olympus is a round lens hood specifically developed for the M.ZUIKO DIGITAL ED 60mm f/2.8 Macro Lens. Lens hoods act to deflect stray light from entering the lens and producing glare. They also add a level of protection for the lens from accidental impact. This lens hood is special in that it has a sliding mechanism and can slide down to retract when not needed. This allows the lens hood to remain on the lens when not being utilized or when stored.