Williams apertures are standard thread size and will accommodate Williams, Redfield and Lyman receiver sights. The Twilight series are designed for shooting under poor light conditions. They create a sharp contrast that gives quick definition to the aperture hole.
- If included in description, the fractional dimension is the outside diameter of the metal aperture.
- The decimal dimension is the size of the hole drilled in the aperture which is actually looked through by the shooter.
- Apertures are standard thread size and will fit Williams, Lyman and Redfield receiver sights.
- The twilight aperture is specifically designed for low-light conditions.
- Big Game aperture is designed to mount on the FP or 5D receiver sight and has an extremely large opening, similar to a ghost ring type of sight.