XS Sights Big Dot Tritium front sights for S&W J Frame and Ruger SP101 was designed for defensive shooting. This sight has a snag free designed that will not catch on clothing and is meant for an easy draw from your conceal carry holster. The large front tritium sight improves speed of target acquisition, while the tritium lamp aid sight alignment in all lighting environments. This Big Dot Tritium will allow you to get on target fast and focus on the front sight, so that you can make a reliable shot. XS Sights Big Dot Tritium Front Sight will be there when the shot matters most. Fits: S&W J Frame and Ruger Sp101 NOTE: Pin Hole Must Be Drilled