The Fat Macs zirconia flap discs are thicker and long wearing than our basic flap disc. Made in Germany, they have multiple layers of zirconia cloth flaps which constantly expose new sharp points to the work surface. Laminated by state of the art automated equipment, they have reinforced fiberglass backing that wears with the flaps and will not damage the workpiece. Balance tested to eliminate vibration and provide a smooth cutting, long lasting sanding tool. These flap discs come in 36 Grit, 40 Grit, 60 Grit, and 80 Grit. Sold in packs of 10 and 100.