This Wiha Tools 6 Piece Metric Hex Bit Set offers a versatile selection of hex (Allen) head bits for use with 1/4" universal hex drivers. The set includes the following: 2.0, 2.5, 3.0, 4.0, 5.0, 6.0. Each bit has been thoroughly hardened for the best possible wear resistance. You know you're getting quality with Wiha!