Allows for flat sanding and edge sanding. Lasts twice as long and removes twice as much material than regular Dremel sanding discs. EZ Lock system allows for 7 times faster accessory changes than regular Dremel sanding discs. EZ Lock sanding discs use the EZ Lock mandrel, Model No. EZ402 (SKU 340535), to make accessory changes easy as pull-twist-release (sold separately).