Weiler 1-1/8″ Knot Wire End Brush features a hollow end and heavy-duty brushing action with some flexibility for more demanding cleaning and deburring applications in recessed areas. 1/4″ stem diameter for use on die grinder and right angle die grinders. This product is clamshell packed for retail. Hollow End and Heavy-Duty Brushing Action with Some Flexibility. Ideal for more demanding cleaning applications in recessed areas. . . .