Mini bench grinder high speed for buffing, for grinding variable speed, 0-10,000 rpm. 31" flexible- ... you need it.The almost 3" dia wheels -- (1) for buffing, (1) for grinding -- are variable speed, up to 10,000 ... you need it. The almost 3" dia wheels -- (1) for buffing, (1) for grinding -- are variable speed, up to 10,000 ...