With seeded-gel, P-graded ceramic alumina abrasive and a laser-cut vacuum hole system that extracts dust to keep your work area clean and protect against contamination, this ProSand? multi-air cyclonic A975 medium grit paper hook and loop center hole vacuum disc is ideal for sanding and finishing aluminum, fiberglass, wood and composites. The hook-and-loop back makes it easy to mount and change discs, while tear strength and flexibility are provided by the latex-saturated, fiber-reinforced C-weight backing. An open coat and water-based, non-pigmented stearate offer maximum load resistance without transferring colors to your workpiece. This disc offers the longest life of any paper disc.