Ideal for preparing metal surfaces for priming and also for opening osmotic blisters before repair, 3M Cubitron II Roloc Fibre Discs are engineered to cut faster, cooler and with less grinding pressure than conventional abrasives. Precision-Shaped Grain (PSG) maintains super-sharp points that cut exceptionally fast with less pressure. Disc life is significantly longer, which results in fewer disc changes.Triangular-shaped ceramic grain wears evenly, runs cool, and optimizes mineral breakdown. Offered in 36, 60 and 80 grits with a choice of 2" or 3" diameter. Box of 15.