3M™ Purple Clean Sanding Disc 334U with 3M™ Hookit™ Attachment System features a precise hole design for improved life and dust extraction. This disc offers the coarsest grade available for fine featheredging and the final sanding step before priming. The multi-hole disc pattern lasts 2-3 times longer than our traditional no-hole, 5-hole or 6-hole discs. It is designed for quicker changes because hole alignment is not required. Use with the suggested 3M™ Backup Pad PN20427 and Soft Interface Pad PN05771.The 3M Hookit Purple Clean Sanding Abrasive Disc 334U cuts fast, lasts long, resists loading and leaves a consistent finish across a wide range of applications. It features durable, fast-cutting aluminum oxide abrasive built on C-weight paper backing. A spiral pattern, made up of many tiny holes, keeps particulates away from the surface to reduce loading. When used with dust extraction systems dust will be captured rather than staying on the sanding surface or floating in the air. This pattern also eliminates the need for hole alignment, making it faster and easier to change the discs and extending the abrasive's useful life. Discs are available in grades P240 - P800, ideal for featheredging, fine featheredging or as a last step before priming. They are also great for prepping before blending. The Hookit Attachment System makes for fast and efficient disc change-outs without tools.