1.Size: 0.1-1mm; 1.1-2.0mm. 2. strictly symmetrical: beneficial and efficient cutting, avoid offset drilling 3.Various drill bit kinds, used in a of application needs 4.Made tungsten carbide bits 5.Fit for: PCB drilling machines, engraving machine, CNC and high precision special drilling equipment Diameter: 0.1-1mm: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm ( 1pcs for each Value ) 1.1-2.0mm: 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm ( 1pcs for each Value ) (Positioning ring color random) Carbide rods and tungsten steel rods, with high hardness, high wear resistance, high strength, resistance to bending, anti-impairment and long tool life Large drill bit chip space, chip resistance,Chip smooth, small drilling heat, reduce smear. Drill has a large scraps discharge space,little resistance and smoothly during the scraps discharge. Using high quality materials and fine grinding process makes bit more sharp ,reduce cutting force and broken drill and improve the quality of hole wall. strictly symmetrical: beneficial and efficient cutting, avoid offset drilling. Color: positioning ring color random Not accept Specify Material: Alloy tungsten steel Package Contents: 2 boxes of drill bits Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.