Abstract: Cases, enclosures, or “road boxes” are custom designed and built using modular components whose lengths and/or heights are provided in multiples of the industry standard length EIA-U to allow compact housing of standard sized components and drawers within the enclosures. The stock materials used to construct the support frames which mount the components and the drawers designed to hold the accessories needed to operate the components are provided as modular elements having unit length dimensions clearly indicated to simplify building the enclosures at different, custom-designed lengths. The assembly of support frames and drawers is further simplified by interlocking elements by means of tongue-and-groove connections spaced to correspond to the same unit length dimensions.