Check the listing for details. 12" in 300mm Diamond Grinding Disc Grit 240 Coated Flat Lap Disk Lapidary Tools. Color: Silver, Condition: New. Listed at 55.00 USD. JINGLING 12" inch 300mm Diamond Grinding Disc Coated Flat Lap Disk Wheel Grit 240 Product Specification: Outside diameter : 12" inch (300mm) Arbor hole : 1/2" (12.7mm) Thickness : 1.3mm Grit : 240 Grit type: Medium Diamond coating Density: Perfectly high Diamond coating surface area : almost 95%, only one side is coated diamond Recommended speed: 1400-2800RPM Wet use recommended Suitable to grinding gemstone, jewelry, glass, rock, etc. These diamond discs are one of the finest discs manufactured for Hobby, Lapidary, Glass applications The diameter flat lap wheels have a high density quality diamond coating. They are absolutely flat and parallel to meet the most exacting faceting requirements. Quick Tips 1. Recommended for rough and fine grinding on faceting material plus general lapidary grinding when precision is required. 2. All our flat laps wheels have a 1/2" arbor hole and are intended to be mechanically clamped to a Master Lap. 3. The laps are made with 1mm thick steel plate that has been machined true and flat. The lap is stiff enough to be used as is, but we recommend with the use of 12 inch Aluminum Master Lap. Also Available in Grits 60, 80, 100, 150, 240, 320, 400, 500, 600, 800,1000 We will send out your order within 1-2 days after payment has been received and cleared. Please let us know if you are looking for other accessories or hardware.