✅ MAX PERFORMANCE – Sicalls premium flap disc set includes 12 pieces of the most commonly used flap discs which are T29 40 grit, and Size 7/8-inch which can be used for many projects such as applications metal sanding woodworking concrete grinding or any other type of finishing, such as making stones smooth. It also works amazing for removing rust and much more. It is designed to help you do all your projects with the maximum efficiency. ✅ LASTS LONG AND WONT RUB OUT – Sicall has put in a huge amount of research and developed the perfect sanding wheel flap disc. Made from hard zirconia alumina, a material which lasts longer than standard aluminum oxide abrasive flap discs that most sellers offer on amazon. We built the flap disc in a way that would get you much more uses than other competitors on the market. ✅ FEATURES - T29 40 Grit 7/8 Inch High Quality Zirconia Discs with extra strong fiberglass backing ensures that it will remove dirt clumps of virtually any type of project that you are using with the one and only Sicall sanding disc