Features: Polishing Laps Mainly used for polishing Crystal, Agate, Jewel and Jade, and suitable to grind and polish jewelry, glass, rock, etc. Diamond coating surface area: almost 97% All our flat laps wheels have a 4" (approx.) outer diameter and 5/8" (approx.) arbor hole and are intended to be mechanically clamped to a Master Lap. Specifications: Product Name: Diamond Grinding Disc Outer Diameter: 100mm (4") Arbor Hole Diameter: 16mm (5/8") Grit: 80 /180 /240 /400 /800 /1000 /2000 Quantity: 1 Pc Note: Please allow 1-3mm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you No Retail Package Package Includes: 1 x Polishing Grinding Disc