Bona 7" Blue Abrasive Discs (5/16" hole) consist of an innovative combination of grit materials and anti-static properties, designed to give you aggressive performance without sacrificing smoothness, at a tremendous value. The addition of anti-static properties helps prevent dust from clinging to the machines, which leads to a more consistent cut, less dust on the floor, less wear-and-tear on your sanding equipment. When other discs stop cutting, Bona Blue Abrasives keep on working with high efficiency and smooth results.