Professional high-quality multi-hole sanding discs with a special hole pattern ensure perfect dust extraction - 3M 325U are durable, reliable, and provide excellent finish quality - they save costs by optimizing results during post-collision repairs - this is an improved version of the popular Montana sanding discs - disc lifespan increased by 30% thanks to the special Free Cut coating preventing the abrasive material from clogging too quickly - aluminum oxide coating with a ceramic grain admixture is appreciated among professionals for its cutting speed and very long lifespan - sanding discs allow for quick installation and removal during grinding - 3M Hookit 325U discs are available in grits from P80 to P600 - best performance in its class on various substrates - for use with 3M 51126 / 3M 51127 backing pads, 3M 51122 / 3M 51123 / 3M 51124 / 3M 51125 / 3M 28729 work discs - also adapted for work discs and tool pads.