A collapsible, foldable support structure and conveyance has a frame assembly with multiple interconnected frame members, junction blocks located at intersecting ends of some of the frame members, and wheels attached to the junction blocks or directly to frame members. The guide tubes are positioned along the outside of the filling body, providing access to the guide tubes during post-installation branching. Instead of using the reducing gas, a carbon-based material having a reduction action may be provided within the target container for causing reduction reaction. The contiguous regions may be specified as an address and a format such as a row, a column, or a neighborhood relative to the address. A ground fault circuit interrupter system and a method are also provided. In addition, the portable unit can be a law enforcement mobile unit.