... .The almost 3" dia wheels -- (1) for buffing, (1) for grinding -- are variable speed, up to 10 ... a 3-pronged grounded plug. Comes with detailed instructions for use and safety, and this reminder from A ... The almost 3" dia wheels -- (1) for buffing, (1) for grinding -- are variable speed, up to 10, ... a 3-pronged grounded plug. Comes with detailed instructions for use and safety, and this reminder from A. ...