The Proxxon 23102 Wrenches set is a Chrom-Vanadium steel set of 23 Torx® wrenches. Torx® is a type of fastener system that utilizes a star-shaped pattern instead of a standard hexagonal pattern. The Chrom-Vanadium steel of the wrenches provides a strong and corrosion-resistant construction that is ideal for use in tough and demanding work environments. These wrenches are designed for use with sizes TX6, TX7, TX8, TX9, TX10, TX15, TX20, TX25, and TX30. This set is ideal for use on small electronics and precision machinery, as well as for maintenance and repair applications.