Dewalt diamond core bit is design for high speed drilling and long life in a wide range of building materials. For use with diamond drills. Standard 1-1/4 Inch UNC female fitment to allow usage with dewalt and other diamond drill brands. Length (mm): 500mm Outer Diameter (MM): 102 Spindle Thread size: 1 1/4 Inch UNC(F) For use with: For use with diamond drills Application: For dry drilling clean large diameter holes in masonry and stone D102X1 1/4" UNC(F)XL500XT3.5MMXW10