Abrasives > Sanding Discs > Flap Discs | Flexovit Mega-Line Blue Flap Disc | Flexovit Mega-Line Blue R828 Flap Disc Flap Discs can grind, blend and finish in one step. Flap Discs can be used to advantage in many applications that involve the use of depressed center grinding wheels and / or resin fiber discs by eliminating two step finishing and tool change time, thereby reducing total job cost.