o These 600 grade discs are used for primer sanding and blend preparation.o Finer finish and long lasting abrasive disc for primer sanding and blend preparationo Stikit(TM) backing for quick and easy pad attachmentStikit(TM) backing for quick and easy pad attachmento Engineered ceramic mineral blend provides best-in-class performance using exactly the right balance of ceramic grain and premium aluminum oxideo Anti-loading coating improves abrasive life while upgraded resins improve durability and finisho Suggested backup pad PN05546