An in-line inspection (ILI) tool 20 for use inspecting pipelines includes a plurality of collapsible guide centralizers 100 configured and sized to correspond to the inside diameter of the pipeline being inspected. The guide centralizes 100 include wheels 102 roll along the inside wall of the pipeline being inspected to maintain the guide centralizers “centered” within the pipeline. A collapsible exciter unit centralizer 200 is positioned between collapsible guide centralizers 100 to “center” the exciter unit centralizer relative to the interior of the pipeline. The exciter unit centralizer 200 generates signals in the form of an alternating magnetic field that travel along the wall of the pipeline which in turn generates eddy current signals. The eddy current signals undergo a change if a discontinuity in the pipeline is encountered by the inspection tool 20, which signal change or deviation is detected by a collapsible detector unit centralizer 300 positioned between the collapsible guide centralizers 100.