The Mercer 182020 2-inch Crimped Cup Brush is constructed for even balance. The Mercer 182020 is made of carbon steel and has a 1/4-inch shank. Features: * Utilizes an internal holding plate to secure brush bristles * 1/4-inch fixture x 2-inch diameter * Bristles are .014 carbon steel * Maximum RPM of 20,000 What"s In The Box: * Mercer 182020 2-inch Crimped Cup Brush