The 3M™ Square/Cross Pad Mandrel secures a square pad, a cross pad, or a cross buff to a rotary tool with a 1/4-inch collet assembly. The external threaded shank must match the internal threaded inserts of the pad or buff to be used. This useful accessory is available in three external thread sizes – 3-48, 8-32 and 1/4-20 external.