This friction grip diamond bur is a round ball. The head is 0.9mm in diameter. The ISO maximum speed is 450,000 RPM. This diamond bur is made for air powered, high speed dental handpieces. Overall length of the bur is 19mm (3/4"). The shank is 1.6mm (1/16"). Available in a medium or coarse grit. Availability: Usually ships in 2-3 business days 0.9mm Round Ball A0.5$3.45Grit: MediumCoarse Thank you for visiting A&M Instruments, Inc. Diamond Dental Burs. You will be pleased with the high quality of your dental burs and dental discs. All of our diamond and carbide cutting tools are made in the US, in Alpharetta, GA. Copyright® 2003-2011 A&M Instruments Inc 770-772-6404