Easy "no-tool" shelf adjustment. Shelves can be repositioned at precise 1" (25mm) increments along the length of the numbered posts. 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. Starter units consist of four posts and the indicated number of Super Adjustable Super Erecta shelves.