The ORIGINAL SHEar & heLIX spiral cutter non-grind design! Made in the USA by Byrd Tool Corp., these indexable carbide insert cutterheads provide a shear, staggered cut instead of a single, straight knife cut. Not only does this provide a superior finish on your work-piece, it is a lot easier on your dust collection system because the configuration of the inserts breaks up the chips. Another benefit to the indexed insert design is ease of maintenance. Dull or damaged insert knives are individually replaced, a much more cost-effective option than having to replace expensive knives the full length of your planer head. Each cutterhead comes with 5 extra inserts and a torque driver to aid insert replacement. The Dewalt DW735 replacement cutterhead now comes in two sizes. The original was sized slightly smaller (.0078 inches) than the OEM cutterhead in order to fit through the hole in the chassis with the inserts still mounted on the cutterhead. This OEM cutter is machined slightly larger to give you a cutterhead that is the same size as the one you are removing. You will need to remove the inserts prior to install, and then replace them once the cutterhead is in place.