The optional 9” round abrasive disk pack includes professional grade abrasive discs which are cloth backed, not paper backed, with high quality pressure sensitive adhesive (PSA).  This combination of premium abrasives with a cloth backing and integral PSA provides superior performance during grinding without leaving residue behind when removed from the grinder’s aluminum disk.  The uniform pressure sensitive adhesive on each abrasive round has protective release paper for ease of application and to keep the adhesive clean prior to use.  This twelve disk kit includes ceramic abrasive rounds in 60, 80 and 120 grit and premium aluminum oxide abrasive in 240, 320, and 400 grit; two of each grit are included in the kit.  The ceramic rounds have a strong Y-weight polyester cloth supporting the long lasting, self-sharpening ceramic grains which contain a grinding aid to help reduce loading and workpiece temperatures.  The aluminum oxide rounds have a durable X-weight cloth supporting premium aluminum oxide abrasive grains which work well on most materials.  Tip: it is easier to remove the cloth-backed abrasive round from the grinder’s aluminum disk while it is still warm from grinding.