Cargo worthy shipping containers are graded just below a new one trip shipping container, and have been in use for a few years. They may have some minor scuffs and dents and some rust on the exterior but are still impervious to the elements. The doors and seals are still in working order and they can even be certified to ship cargo if that is your need for a shipping container. These conex boxes are great for converting into a mobile field office for construction companies to move from jobsite to jobsite. There are many fabrication companies out there that have the expertise to convert these shipping containers into many different types of shelter.