Four secondary conduits, including Leon Sinks, intersect the main conduit. These tools are ineffective for locating plastic conduits or concrete storm and sanitary sewers. A duct bank is usually made of multiple PVC conduits encased in concrete. Wires must be protected from sharp metal edges of cut conduits or cabinet holes. The Hybrids are cyborgs, consisting of conduits and other connectors mated to biological elements. The push rods also acted as conduits for oil flow to the valve gear. It was connected to two axial conduits. Flowing water in karst conduits carries the soil away allowing the process to continue. Rivers and streams are not only conduits of water, but also of sediment. The propulsion section consists of the rocket motor, external heat shield, and two external conduits. Many biomaterials used for nerve guidance conduits are biomimetic materials. Scattered springs would require several branch conduits feeding into a main channel. Most of these secondary conduits have been fully explored. There were two ways to use these conduits outside these hubs. Inspection and access points were provided at regular intervals on the standard, buried conduits.