abrasive with press-on/flip-off center hole feature. Exlclusive grit ang backing are designed for dental finishing and jewelry applications and provides outstanding results in sanding and smoothing operations. The flexible backing allows accessibility to hard-to-get-areas. Used with 3/32" (2.4mm) mandrel. Sold in master pack - 12 boxes of 50 discs per box. Coarse 1/2" (13 mm).