Forney 71992 Flap Disc, Type 29 Blue Zirconia with 5/8-Inch Arbor, 60-Grit, 4-Inch Blue zirconia flap discs for right angle grinders Cuts fast and outlast sanding discs 10 to 1 for long life Multiple layers of zirconia cloth flaps constantly exposing new extra sharp grinding points Great flexibility for difficult work Ideal for rough or fine finishing