These mini diamond points are for use in high-speed, air-driven turbo handpieces with a maximum operating speed of up to 80,000rpm. Shanks measure 1/16" (1.6mm) in diameter with an average length of 3/4" (20mm). Excellent quality with diamond particles in fine and coarse grits electroplated onto surgical grade steel. Available in Coarse or Fine grits. Also sold individually, see "Related Products" below. Sets of 12 contain shapes A, C, D, E, G, I, O, Q, S, U, V, and X. Sets of 24 contain 1 each of all 24 shapes, A through X. Use of a coolant will maximize tool life, use water or our Lubricant/Thinner. x