3M HOOKIT CLEAN SANDING DISCS 360L – An aluminum oxide, open coat, non-loading Hookit™ disc with precise multiple hole design for improved dust extraction. Designed for use on gelcoat. Not recommended for sanding coatings, as this abrasive contains no 3M Fre-Cut to prevent loading. Constructed on a film backing. MOS: 12,000 RPM. Discs are 6″ in diameter. Sold by the box of 100 discs.