Goodway Tube Cleaning Flare Brush for with Cobalt Tip for 1"- 2" (25.4mm - 50.8mm) ID Boiler Tubes. Flare Brushes incorporate centrifugally activated wire cables with cobalt tips that lightly "whip" around on the inside of tubes removing scale and deposits. Designed for light descaling and finishing of straight or curved tubes. For tubes 1"-8" I.D.