Fixed rear sight fits the GI-pattern dovetail and provides an improved sight picture while maintaining your pistol's stock appearance. An extra-wide .135" notch puts more light around the front blade to aid in faster target acquisition. 50 lpi horizontal serrations on the rear face help eliminate glare. A setscrew locks the sight into the dovetail for a secure installation that won't shoot loose, yet still allows drift adjustments for windage. Rounded corners help resist snagging during the draw from concealment. Precision machined from steel barstock to look good and handle the knocks of daily carry. The 1911 Retro Rear U Notch Sight is made to the same specs as th Mfg: Harrison Design & Consulting SPECS: Steel, matte black finish. .344" (.87cm) length, .622" (1.8cm) base width, and .317" (.8cm) overall height. .135" (.34cm) wide x .135" high notch. Fits GI-pattern 1911 slide dovetail.