Cup Brush, Product Type Cup Brush, Quick Change System Not Applicable, Bristle Type Crimped Wire, Bristle Material Carbon Steel, Brush Dia. 1 1/2 in, Wire Dia. 0.012 in, Bristle Length 5/8 in, Grit Not Applicable, Compatible Tool Type Straight Grinder, Drill Press, Impact Driver, Pencil Grinder, Color Not Applicable, Connector Type Shank, Connector Size 1/4 in, Operating Speed - Maximum 13,000 RPM, Series Gemini