Weiler 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 in Dia stem for use on CNC/milling/automatic machine, die grinder, drill, drill press, right angle die grinder and straight grinder. Hollow end and heavy-duty brushing action with some flexibility. Ideal for more demanding cleaning applications in recessed areas. Rugged knot-type construction provides aggressive, high impact action.