Save time and money by eliminating adjacent posts and replacing with "S" hooks. Open-wire design minimizes dust accumulation, allows a free circulation of air, and greater visibility of stored items. Corrosion resistant Metroseal Green epoxy finish features Microban antimicrobial product protection to keep the product "cleaner between cleanings". 12-year warranty against rust and corrosion. Add-on units consist of two posts and indicated number of Super Adjustable Super Erecta shelves along with two "S" Hooks per shelf, for attaching shelf to adjacent unit.