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 to 3X longer than our traditional no-hole, five-hole or six-hole discs. It is designed for quicker changes because hole alignment is not required.