High-quality aluminum oxide grainClosed coat structure for more material removal and better finishingGeneral purposeAvailable in Bulk, Blue Line??????????or Sait-lok??????????Packaging, Resin over resin construction for a strong bond that is resistant to heat and moistureVulcanized fiber backing for heavy duty sandingBulk Spindle Packaging: Assures that each disc remains perfectly flat. The unique design offers the convenience of easy access and can be retightened to ensure that your discs are flat when you need them.Blue Line??????????Packaging: Used for retail packaging in convenient smaller quantities. UPC bar coded.SAIT-LOK??????????Quick Change 5/8-11" Hub: Extends disc life and requires fewer disc changes. Must be used with a treaded backing pad. Available in Blue Line??????????Packaging only.Custom Discs: All custom fiber discs are non-cancellable and non-returnableBacking Pads for Fiber Discs?????re available in Accessories