Grit 400, 7-inch outside diameter,quality electroplated diamond coated flat lap disk wheel. The flat laps wheels have a 1/2-inch arbor hole for rotary tool. They are absolutely flat and parallel to meet the most exacting faceting requirements. For grinding and polishing jewelry, glass, rock,stone, granite,etc. Recommended for rough and fine grinding on faceting material plus general lapidary grinding when precision is required., Weight: 0.46958461806 Pounds, Manufacturer: Sourcingmap