Apparatus for use in a gastrointestinal tract of a subject, the apparatus including a straightening rod, and a flexible tubular anchor having a distal end and an open proximal end, and sized to fit in the gastrointestinal tract. The unit comprises a solid dielectric structure provided with an interior space wherein an interior electrode is arranged. 5 second has elapsed since the display unit starts displaying the image of a logo mark, the control unit controls the display unit to change the display from the image of the logo mark to a two-dimensional code. A pretensioning element is mounted in the casing of a first ring in frictional contact with the second ring in order to apply a resistant torque during the rotation of one ring relative to the other. The injector medium is operably disposed with respect to the tunnel medium and the high K charge blocking and charge storing medium to provide charge transport by enhanced tunneling. A rectifier means for rectifying the switched AC signal and providing a rectified DC signal.