Pear shaped felt bobs are made of 100% wool felt and mounted on 3/32″, 1/8″ or 1/4″ steel shanks. These felt bobs are ideal for using on die grinders, electric drills and air drills. The maximum operating speed for felt bobs is 15000rpm. They can be used with various polishing compounds or rouges to produce a clean, high finish on moulds, dies, models, all metals, plastics, glass or crystal. Great for polishing and buffing all hard to reach surfaces. Medium and hard density is available.