Milwaukee Tool, 48-13-5004, Adjustable-Depth Drill Countersinks: Cutter Head Diameter (Inch): 1/8, Collar Thickness: 0.6000 in, Drill Size Compatibility (Inch): 0.25, Cutter Head Diameter (Fractional Inch): 7/32, Cutter Head Diameter (Wire): #12, Cutter Head Diameter: 0.2188 in