Our 3Mâ„¢ Hookitâ„¢ Blue Abrasive Sheet Rolls 321U delivers best-in-class performance at every stage of paint prep and coatings removal. Premium aluminum oxide mineral is blended with ceramic grain for a full range of sanding applications. A specially-designed multi-hole pattern captures dust, reduces loading and extends sheet life. Perforated Hookitâ„¢ sheets are easily sized to reduce product waste.