1" x 1/4", High Performance, Carbon, Knot Wire End Brush, .020" Wire, Highly Specified Wire Grades Are Constructed With Internal Holding Plate To Ensure Consistency & Safety, Even Balance Which Provides Smooth Performance, Wire Is 100% Inspected To Meet Demanding Quality Specifications, 1/4" Stem Arbor Size, Maximum Speed Is 20,000 RPM, Knotted Wire Is For Heavy Material Removal, Crimped Wire Provides Flexibility For Light Removal Of Rust & Paint, General Cleaning.