Check the listing for details. 10 - 3" Type S 40-Grit Zirconia Mini Flap Disc w/Poly Backing. Condition: New. Listed at 19.99 USD. YOU WILL RECEIVE BOX OF 10 - 3" Type S 40-Grit Zirconia Mini Flap Disc w/Poly Backing PLEASE NOTE ::: NO RATING ON BOX FOR SPEED NOR IS THE DISC LABELED OTHER THAN THE MASTER BOX . I WOULD NOT USE OVER 20,000 RPM ..BUY AT YOU OWN DISCRETION... Type-S discs feature turn-on/off fasteners.Type 27 flap discs are less aggressive and are used primarily on flat surfaces for grinding a smoother finish.More durable than aluminum oxide, zirconia-alumina is best for medium- to heavy-material removal. The material grains constantly fracture to produce new sharp edges. Commonly used on carbon steels, aerospace alloys, nickel alloys, aluminum, cast iron, forgings and some stainless steels PAY SHIPPING ON THE FIRST ORDER AND REST SHIPS FREE. Abrasive MaterialZirconiaApplicationCarbon Steel, Stainless SteelAttachment TypeType TS (Type II)Backing MaterialPolyCoat TypeClosedColorBlueDensityStandard DensityDiameter3"Disc Backing WeightYGradeCoarseGrit40TypeFlap DiscType NumberType 27 YOU WILL RECEIVE 1 BOX OF 10