Gardex is a completely self-contained conduit/wire system with a continuous, impervious corrugated armor/sheath that provides a positive gas and moisture barrier. The term sheath and armor can be used interchangeably in this construction since the metallic component forms a sheath around the cable of high strength, thereby acting as an armor. This sheath can serve as electrical shielding for many applications, including control cables in substations. Aluminum is primarily used for the armor/sheath, but other materials including copper may be used for special constructions.