XS Sights Standard Tritium Dot Front Sight White S&W J Frame & Ruger SP101 Standard Dot is larger than most front sights, covers less of the target than the Big Dot;White dot reflects ambient light for low light visibility;Outside diameter is 0.140""; fits in common holsters;Installation requires a drill press to drill the retaining pin hole in sight body;Fits S&W J-Frame and Ruger SP101 with fixed reartable.productattributes, .productattributes td { border-bottom: 1px solid #ddd; border-collapse: collapse; padding: 2px; text-align: left; } Item Category Code: 7600 Product Group Code: 7600J Product Sub Group 1: 7600J3 Inactive: No