3M 31364 Cubitron II Hookit 3 in. 180+ Grit Clean Sanding Abrasive Disc (50/Box). The Cubitron II Hookit Clean Sanding Abrasive Discs 737U combines the highest 3M technology for automotive repair. Its long-lasting triangular shaped grain and multi-hole pattern for superior dust extraction make the disc ideal for paint removal, rough body filler shaping, fine feather-edging or final prep before blending or priming.