Non-woven, cotton fiber, bonded with aluminum oxide abrasive retains its shape well and is ideal for finishing, polishing, final shaping, and removing scratch marks. Non-loading; works great on aluminum and brass. Starter Kit has one wheel of each grit packed in a compartmented kit box. Refill paks contain three wheels of one grit. 1⁄8" shank fits hand-held, high-speed, rotary tools. Mfg: Brownells SPECS: 1/8" (3.2mm) Shank. ¼" (6mm) diameter x ½" (12.7mm) long cylinder or ½" diameter x ½" long cylinder.