Fits STI 2011 pistols and clones with front sight dovetails machined to STI specs - .300"wide x .060" deep x 60 degrees. All 2011s require a front sight with correctly dimensioned and engineered dovetails to fit properly. The best front sight on the market is made by Dawson Precision and I am pleased to offer it to compliment my rear sight product line. The DP fiber optic sights are machined from hardened steel and equipped with a red 1mm fiber optic rod for enhanced daylight visibility. They are offered in ramped profile .180" tall x .125" wide.