1 inch x 1/4", high performance, carbon, knot wire end brush,. 20 inches 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.