This product is a Weiler Cup Brush, measuring 3-1/2 inches in brush diameter, with a 5/8-11 UNC arbor hole size. It features standard/twist knot filament/wire type, 0.023 inches filament/wire diameter, steel fill, and 7/8 inches trim length, with a maximum speed of 13300 rpm. It is designed for use on portable power tools for addressing larger surface areas more efficiently than a wheel brush, and is intended for smooth and efficient operation on angle grinders to make quick work of large jobs. The cup brush is available in a variety of knot wire and crimped wire configurations for use in a broad range of surface cleaning applications, and it is manufactured with individual knot hole and solid ring construction