Milwaukee Tool, 48-13-5000, Adjustable-Depth Drill Countersinks, Cutter Head Dia (Wire): #6, Cutter Head Dia (Inch): 1/4, Drill Size Compatibility (Inch): 9/64, Drill Size Compatibility (Wire): #6, Drill Size Compatibility (Decimal Inch): 0.1406, Drill Size Compatibility: 0.1406 in, Collar Thickness (Inch): 1/4