THE ""PATRIOT®"" DUAL DIAMETER BRUSH IS RECOMMENDED FOR REMOVING SOFT (MUD ALGAE ETC.) DEPOSITS IN STRAIGHT FERROUS AND NONFERROUS INTERNALLY ENHANCED TUBES. THE LARGE DIAMETER END OF THIS BRUSH CLEANS INTO THE GROOVES WHILE ITS SMALL DIAMETER END CLEANS THE LANDS OF THE TUBE'S RIFLING. FEATURES UL STYLE""MARGIN-TOP0PX; PADDING-TOP 5PX; PADDING-BOTTOM 5PX;"" ENN-062 - FOR TUBES 5/8"" (15-7/8MM) I.D. DURABLE AND LONG LASTING AVAILABLE IN QUICK CONNECT AND THREADED OPTIONS FOR SOFT AND LIGHT SCALE/HARDER DEPOSITS HIGH QUALITY DUAL DIAMETER NYLON BRUSH AVAILABLE IN TWO SIZES ONLY