Felt Bobs are made from the finest 100% wool for long life. May be used with various polishing compounds or rouges to produce a clean, high finish on molds, dies and models. Felt Bobs are designed to polish, deburr, lap and/or buff work pieces with provide fine detail and tight corners. Polishing felt bobs feature an extra fine, clean wool blend that won't scratch delicated surfaces. use on metals, alloy, glass, plastics, fibreglass, and composites.