Construction and Performance of IP Optics Tuning Knobs in the LHC

During the first years of operation of the LHC unknown field errors or misalignments could lead to unmatched optics and discrepancies with respect to the model. This could affect some critical parameters such as the luminosity or the lifetime. It is therefore desirable to implement tools which allow for ne tuning of the IP optics and could be used during the commissioning phase of the LHC. In this paper we report on the implementation the performances and the limitations of these commissioning tools.