Ko-ken RS3127/8 3/8 Sq. Dr. Nut Twister Set, 8mm-16mm. This 8-piece set is designed for removing rounded-off bolts and nuts using its unique Nut Twister sockets. Each socket features six teeth with a special helical structure that tapers inward, providing a secure grip on rounded fasteners. Suitable for use with stud bolts, cap bolts, and other rounded bolts, the set includes sizes 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, and 16mm, each with a 32mm length. The sockets are mounted on a 200mm rail for easy organization and access. With a 3/8" drive, this set is a versatile addition to any toolkit for dealing with problematic fasteners.