F100 - 40 Grit Diamond Bur - 3/32" Shank (Made in the USA) 40 Grit Diamond Bur - 100% Natural Diamond (not synthetic) Diamond Flame Shape - Head Length Approx 13mm - Head Diameter Approx 6.75mm Works great for grinding down all types of stone, including fire agate 40 Grit works best for bulk removal High quality diamond bur. Made in the USA.