The answer for extracting broken screw and bolts\n Designed with a center point for centering drill hole, 8 points of contact and cutting edges to eliminate slipping, and hexagonal driving heads for optimal torque\n Includes pieces capable of handling bolts ranging from 3/16"3/4" (4.76mm19.05mm)\n Constructed from high alloy German chrome vanadium steel\n Comes in metal storage case\n 3/16"3/4" (4.76mm19.05mm) bolt/screw capacity\n Made in Germany