As the original wire storage shelving system and still the industry leader, Metro shelving continues to evolve and aims to meet the diversity of todays storage challenges. These professional grade units hold more weight. The four (4) shelves can be positioned, or re-positioned, at precise 1 increments along the length of the posts. Open wire design minimizes dust accumulation and allows for free circulation of air and greater visibility of stored items. Casters (sold separately) available for mobile applications. This post-based shelving system, created in 1965, is recognized worldwide as the most popular commercial shelving system ever. Assembly required