Hoodmans glasses model hoodeye eyecup for nikon square eyepiece 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 nikon square eyepiece 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 irritation at