Z-Discs are made of a special blend of zirconia, diamond and ceramic composites. The exceptional combination of thinness (ultra-thin), strength, durability, and cutting qualities have made this disc the perfect abrasive disc for cut-off of e.max sprues, for finishing of ceramic bridges, for fine detail contouring of interproximals, and for contouring green state zirconia. The additional plus is that there is no contamination. Size: .20 x 22 mm. Box of 25 discs. ADVANTAGES: Ultra-Thin Abrasive Disc; Strong & Durable; Excellent Cutting Qualities; No Contamination; Great Value. USES: Cut-off of e.max sprues; Finishing of ceramic bridges; Fine detail contouring of interproximals; Contouring of green state zirconia.