Mercer Abrasives is an industry leader in quality and performance. Mercer Abrasives premium Aluminum Oxide Flap Discs are "general-purpose" and are great for rust removal, light deburring, and all-purpose grinding and sanding. Mercer Aluminum Oxide Flap Discs come in 5/8", 5/8"-11, and 7/8" Arbor sizes. These Mercer Flap Discs also come in either Standard Density or High Density. High Density has 40% more cloth than standard and provides a longer life and softer grind. Mercer Flap Discs can come in Type 27 flat shaped discs or Type 29 conical shaped discs which are ideal for a more aggressive cut. Mercer Flap Discs grit ranges from 36 to 120.