Part # 71229. SAIT Flap Disc. Encore. 5 inch X 7/8 inch. Z. 10 per pack. Zirconium. 80 grit. Type 27. Application: Grinding, Blending, Finishing. MAX RPM: 12,200. General purpose specification - however, contains larger and more flaps than the competition providing longer life. Premium zirconium grain on cotton backing which provides long life and high stock removal. Will not contaminate stainless steel. Resists loading on aluminum. Fiberglass backing plate. Arbor: 7/8.