WILLIAMS WGRS-HR Receiver Peep Sight 17778 These compact low profile sights are lightweight, strong and rustproof with positive windage and elevation locks. In most cases the sight utilizes the dovetail or existing screws on top of the receiver for installation. Some guns will require drilling and tapping to install this sight. Notes: Sight is made to fit 1/2 radius barrels or receivers with 1 hole spacing. NOTICE: ALL WGRS RECEIVER SIGHTS ARE FURNISHED WITH THE STANDARD R-3/8 X .093 LONG SHANK APERTURE. 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.