Heat-treated chrome molybdenum steel extractors with reverse spline thread for maximum grip. Handy case supplied. Removes broken or unwanted screws, bolts and studs. Designed for high torque applications. For use with 13mm hex socket. Includes extractors size (3.2, 4, 4.8, 5.5, 6.3, 7, 8, 8.7, 9.5 and 10.3mm).