Diamond coating covers approximately 97% of the surface for efficient polishing and long life. Designed for flat lap use Outer diameter is 100 mm (4 inches) with an arbor hole of 16 mm (5/8 inches). Intended to be mechanically clamped to a Master Lap for secure, consistent performance. Package contents 1 Polishing Grinding Disc Outer Diameter: 100 mm (4') Arbor Hole Diameter: 16 mm (5/8') Grit options: 80, 180, 240, 400, 800, 1000, 2000 Polishing laps use and capabilities Mainly used for polishing Crystal, Agate, Jewel and Jade. Suitable to grind and polish jewelry, glass, rock, and related materials. Quality and condition Brand and Specifications and compatibility Diamond coated for durability and fast material removal Compatible with Master Lap systems when clamped mechanically Grit range supports progression from coarse shaping to fine polishing Practical applications Finishing gemstone cabochons (crystal, agate, jewel, jade) to a gloss surface Prepolish and final polish on glass items, beads, and decorative rocks for jewelry or craft projects Refining small jewelry components or beads during jewelry making and repairs