The 80 Grit SG2 (photo shown is 150 Grit) is a wheel shaped diamond bur. The approximate head length is 3mm, and the approximate head diameter is 5mm. This bur is great for grinding or carving all types of stone, glass, tile, metal, wood and more... The 80 Grit is intended to be used for bulk removal and rough cutting. Inverted cones are great for undercutting. As with all Lasco Diamond Burs, the 80 Grit SG2 is a high quality, durable, 100% Natural Diamond bur, and is made in the USA. The SG2 is also available in 80 Grit, 150 Grit, 200 Grit, 400 Grit, and 600 Grit.