3M 5" & 6" "Hookit" Microfinishing Discs are waterproof and ideal for wet or dry sanding. The heavy duty loop backing makes these 3M discs compatible with any 5" or 6" random orbit sanders with hook and loop pads. The great advantage of hook and loop is that the microfinishing discs can be reused over and over greatly extending their longevity and reducing your finishing costs. These disks also work perfectly well with 5" and 6" sanders lacking dust collection. They are sold in quantities of 10 per grit size and boxes of 50 per grit size, or you can try 10 piece assortment of 2 sheets each grit. 5" 8 Hole Pattern Discs fit Ryobi RS 200, DeWalt DW421, Makita B5000 and Bosch 3283DVS and other sanders with a similar hole pattern.