This invention presents a security barrier post which has an underground footing and an impact post that extends above the surface. The method of producing a bone screw includes forming a one-piece headless screw body out of a rigid metallic foam that is entirely porous throughout and defines a plurality of inter-connected pores having a size of about 30 to about 500 microns in diameter. At least one multi-region instrument in the set of user defined instruments is identified. The replaceable shearing tip has two L-shaped sections which engage the upper jaw between them. An external diagnostic interface contains a further identification unit and it is enabled and the data in the at least one further data bus system are thus accessible only after an authorized diagnostic tester has been identified. A control unit provides a high-frequency control signal to the primary winding.