Hoodmans glasses model hoodeye eyecup for canon 5d and 5d mark ii models is specially designed for the eyeglass wearer from its over sized design which seals out ambient light to its rotating nature that accommodates right or left eyed shooters this eyecup ensures that the bespectacled canon 5d and 5d mark ii shooter can get their shot with ease the self locking mount slides over the eyepiece mounting rails keeping the cup in place additionally the hypoallergenic silicon keeps irritatio