Get in Tight With These Buffs. The fine-weave cotton of this mushroom-shaped buff works faster than conventional felt bobs and also lasts longer. The 1/4" hex shaft resists slipping in your drill chuck while its plastic ferrule prevents scratching the recessed areas of your workpiece. These unique buffs will help you reach into deep recessed areas on your project. Great to use when the area is too large for a felt bob. Like the larger mushroom buff above, they feature 1/4" hex shafts and plastic ferrules. Max. rpm 10,000.