This is an interchangeable style Ruger MK I, II, III and MK IV front sight.Part number HRB2007Interchangeable LitePipe designIncludes green, red and white LitepipesAll steel constructionLitePipe diameter 0.090Blade width 0.125 XFactory height front sight compatible with factory rear sightLimited lifetime warranty under normal conditions and proper use of firearmReplacement LitePipe Handgun version #3Fits Ruger Mark I, II, III and IV steel bull barrel pistols; 22/45 with adjustable rear sight (does not fit 22/45 LITE); Single-Six revolvers with adjustable rear sight. Also fits Browning Buck Mark pistols (does not fit Challenge, 5.5 Target, and 5.5 Field).