A system for providing information through a metal wall employs a device adapted to be arranged on one side of the metal wall and a magnetic-permeability element, provided at, near or connected to the device. The magnetic-permeability element is based on a material having a relative magnetic permeability of at least 2000. The disclosure also provides use of said system. The use may involve the step of optimizing the magnetic-permeability element using equivalent inductive mass (EIm). The system can for example be used to magnetically sense the location of a cable present on the outside of a wellbore tubular using a magnetic orienting tool that is located within the wellbore tubular.