These mini flap wheels feature abrasive Aluminum Oxide grain embedded in a flexible backing cloth. Due to their flexibility they adapt easily to the contours of the work piece. They are ideal for sanding smaller confined areas and hard to reach surfaces. The flap wheels are available in several different grits and sizes. The 1/8" shank fits most flex shaft and rotary tools. Industrial quality. Made in Germany. Max RPM 50,000. The sizes below refer to flap wheel head diameter and head length.