Century Drill and Tool 36406 Lazer Spade Bit Set, 6 Piece Lazer spade bits advanced cutting design features arched shaped cutting spurs that define the hole remove the chip and increase cutting speeds Heavy duty single construction shank provides added stability to eliminate wobble Made from premium quality hardened steel remains sharper longer and increases tool life 6 piece set includes 3/8-Inch 1/2-Inch 5/8-inch 3/4-Inch 7/8-Inch and 1-inch lazer spade bits Power shank fits all types of 1/4-Inch quick-change adapters