【Dimension】- Granularity: 240-grits; Wheel Size: 20mm x 16mm / 0.79-inch x 0.63-inch (D*L); Shank Diameter: 3mm / 0.12-inch..【Material】- The handle of this shank grinding head is made of stainless steel, the abrasive part is made of alumina material, and gauze is used as the back base material. Splendid performance because of the high quality material and special design..【Performance】- Alumina abrasive sander is continuously exposed to prevent clogging and give a uniform finish,Best as a finishing sander after heavier surface sanding and material removal is completed..【Note】- The mounted flapper wheel suitable for most of drill. Please rotate clockwise when using, do not use it counterclockwise..【Application】- Sanding flap wheel is suitable for smoothing, rust removal, cleaning, deburring, surface grinding, decorative grinding, faceting and so on. Great on non-metal and metals. Ideal for grinding and polishing flat or contoured surfaces on a wide range of material.