The Williams Ace in the Hole Base Set is uniquely designed to accommodate optics such as scopes while retaining iron sights. Incorporating an integral Picatinny rail into the rear peep sight assembly, and combining it with the glowing affects of the high contrast fiber optic front sight, make these sights perfect for use with a wide range of red dot, holographic, and magnified optics. Each set includes a Fire Sight red fiber optic front sight and 3/8" x .093 rear peep aperture. - Fits Ruger 10/22 - Red Fiber Optic Front Sight - CNC Machined High Grade Aluminum - Picatinny Scope Rail with Integral Backup Sight - Interchangeable Apertures and Ghost Rings - Adjustable for Windage and Elevation About Williams Williams Gun Sight Company was started in 1926 by Harvey Williams as a sight manufacture. The company grew its sight manufacturing business over the years then developed a retail store and shooting ranges in Davison, Michigan. In recent years, Williams is the oldest sight company that provides sights to many different gun manufactures.