The major strength of UNITS Portable Storage is in the experience of our sister company, Extra Room Self Storage, LLC, with fixed self-storage locations in the coastal Carolinas. Extra Room Self Storage, LLC, a South Carolina based company was established in 1999. The Extra Room Self Storage space inventory is projected to be 250,000 square feet by the end of 2007. Through this process of continued growth, we strive to meet the needs of every customer.