A&H Abrasives 949692, Sanding Discs, Zirconia Alumina, (y-weight), 12" PSA Zirconia 80 Grit Cloth Sander Disc Zirconia alumina discs will last longer on general to heavy metal and woodworking applications. Specifications: Diameter=12 in, Shape=ROUND, Attachment Method=PSA Specifications: Grit=80, Abrasive=ZIRCONIA ALUMINA, Abrasive Bond=PHENOLIC RESIN Specifications: Backing=CLOTH, Backing Weight=Y