3M Hookit Blue Abrasive Disc 321U delivers best-in-class performance at every stage of paint prep and coatings removal. Premium aluminum oxide mineral abrasive is blended with ceramic grain for a full range of sanding applications. Our multi-hole discs feature a specially-designed pattern that reduces loading, extends disc life and aligns with most backup pads. Hookit attachment makes disc changes easy.A best-in-class abrasive for the entire repair and paint prep process.