Sights: Aperture (Peep)
Aperture (Peep) Sight: Combination of a bead or post front sight and a round hole set on the rifle’s receiver close to the shooter’s eye. To aim, you center the target in the rear peep or aperture sight, and then bring the front sight into the center of the hole. An aperture sight lets you aim more accurately and is adjusted more easily than an open sight.