Our 3M Hookit Blue Abrasive Disc 321U delivers best-in-class performance at every stage of paint prep and body repair. Premium aluminum oxide mineral abrasive is blended with ceramic grain for a full range of automotive 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. Engineered ceramic mineral blend is balanced for maximum abrasive performance in its class. Discs available in mutli-hole pattern for excellent dust extraction or in no-hole format. Anti-loading coating prevents dust and debris from clogging the cutting surface. Upgraded resins improve durability and finish. Hookit attachment makes changing discs fast and easy