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 H&L 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 work piece. This disc offers the longest life of any paper disc.