Wera 851/1 IMP DC Impaktor TriTorsion Long Service Life Bit, for Phillips screws. Impaktor bits maximise utilisation of material properties using a very special geometry designed to meet extreme working demands. The combination of a double torsion zone in the Impaktor holder and a torsion zone in the Impaktor bit results in a TriTorsion system. The TriTorsion system is designed to absorb impact forces and thereby protects the bit tip, greatly enhancing the service life of the bit. Impaktor bits also feature miniature diamond particles on the tip of the bit that literally bite into the screw, creating a secure fit in the screw and preventing any slipping out from occurring. Such a secure fit means that less contact pressure is required, this therefore greatly delays user fatigue in power tool applications. Take it easy tool finder is used in accordance with profile and size, for fast and simple selection of the required tool. Impaktor bits are designed for long lasting use with impact screwdrivers, for optimum service life use with our Impaktor bit holders.