October Mountain Retna Peep Sight 3/16 in Green. The aperture design provides a clear round sight picture even when slightly misaligned. Available in three standard sizes. Features of October Mountain Retna Peep Sight: Made from 6000 series aluminum Features deep wall string and serving groves Clear round aperture that forgives peep misalignment Package Contents: October Mountain Retna Peep Sight October Mountain 1601206: Retna Peep Sight 3/16 in Green