Features:Made of diamond materials. high hardness, durable in use.Drill bit set, high strength, corrosion resistance and oxidation resistance.It is widely used in metals, agates, gems, pearls, pendants and pebbles.Tipped drill bit, can be uses with the drills, simple to use.Easy to install and disassemble, which can well improve your work performanceSpecification:Diamond Tipped Drill Bit Set Twist Drill Bits 10pcs/SetSize: 0.8 / 1.0 / 1.2 / 1.5 / 1.8 / 2.0 / 2.5 / 3.0 / 3.5 / 4.0mmThe Length of Twist Drills: Approx. 75mm/3.0in Approx. 65mm/2.6in Approx. 60.5mm/2.4in Approx. 53mm/2.1in Approx. 46.5mm/1.8in Approx. 43mm/1.7in Approx. 38mm/1.5in Approx. 34mm/1.3in Approx. 30mm/1.2in Approx. 23.9mm/0.9inUse Range: Metal, Agate, gemstones, pearls, pendants, CobblestonePackage Includes:1 x 10pcs/Set Diamond Tipped Drill Bit Set Twist Drill Bits Note: Different material hardness, the effect is differentThe color of Package in random.