Starrett XA2 Quick-Hitch Arbor with Carbide Tipped Pilot Drill Carbide tipped pilot drill Fits hole saws from 1 1/4" to 8 9/32" 7/16" Hex shank for use in 1/2" chucks Quick-Hitch arbors enable instant change outs of hole saws without additional tools and without removing the arbor from the chuck Set screw in body allows for easy replacement of the pilot drill