The Merit adjustable peep sight aperture fits WGRS and EABCO PeepRib peep sights. It replaces the original aperture and has an adjustable peep hole. Turn the outside and the hole gets larger or smaller. It allows you to fine tune your peep image for the best clarity and visibility in all brightness conditions. The Merit adjustable aperture is 1/2 inch in diameter and simply screws into your original Williams WGRS or EABCO PeepRib sight. You might also be interested in the Merit Eyeglass Aperture. See all of our TC muzzle loader accessories at our Muzzle Loader Home Page.
(Note: Threads on this aperture are standard 7/32 x 40)