A CONEX (container express) is a storage device used by the military often for mass transport of items. CONEXes have been transported by ship, train, plain, trailer truck, and possibly a number of other ways. CONEXes are built of heavy corrugated metal with thick swing-lever doors, each of which can accomodate a padlock for enhanced security.
Another use the military commonly assigns to the massive containers is improvised permanent or temporary housing. CONEX buildings can consist of a single part, or many parts welded together to create formidably sized buildings.