Garryson DIY Zirconium Flap Disc 100 x 16mm - 80 Grit FineFlap discs have been developed primarily as an alternative to sanding discs and can be fitted directly onto an angle grinder without a backing pad. Lasting up to 25 times longer than sanding discs they also provide a much better finish which will remain constant throughout the life of the disc. These zirconium flap discs suit the majority of metal grinding applications. Size. 100 x 16 x 80g. Fine.