3M Catalog# 31381, 3M™ Cubitron™ II Hookit™ Marine Sanding Abrasive Disc 737U, 31381, 6 in, 120+, 20 discs per box, 4 boxes per case Our Cubitron™ II Hookit™ Marine Sanding Abrasive Discs 737U combines the highest 3M technology for marine 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. Our Hookit™ system makes for quick disc change-outs. UPC: 00051131313811