The Flap Disc is designed for fast material removal applications on all hard, brittle materials without the need for high pressure. This flap disc comes with a combination of diamond and silicon carbide flaps on a reinforced plastic backer pad. Each flap makes line contact so that the disc will maintain fast, aggressive cutting without having to apply pressure. Although it is designed for high-speed angle grinders, for the best results, We recommends using at 8,000 rpm if the grinder has a variable-speed control switch. While the Flap Disc is great for dry use, it can be used wet to keep the dust down, for higher performance and a longer life