Harvey Tool 894532 Diamond-Pattern Router Bits; Cutter Diameter (Inch): 1/2 ; Cutter Diameter (Decimal Inch): 0.5000 ; Shank Diameter (Inch): 1/2 ; Shank Diameter (Decimal Inch): 0.5000 ; Overall Length (Inch): 4 ; Overall Length (Decimal Inch): 4.00