1). Production: Velcro Abrasive Disc. 2). Grit: 16#---400#. 3). Diameter:4", 4.5", 5", 7", 9" 4)Backing: Velcro. Triangle-shaped Abrasive Velcro DiscsMaterial: Aluminum oxide, black silicon carbide, zinc-striate coated; Features: Velcro disc is made of flannel coasted on the abrasive paper or cloth backing, it can be punched to circular, triangle, or other special shapes, it is easy to be fixed ...