Jracking Structural steel H Column Cantilever Rack is a multi-level high density storage system designed to storage long and irregular length materials. It is the most efficient and affordable way to store lumber, engineered wood products, re-bar, metal roofing, pipe, etc. I-Beam Cantilever can be used indoors or out. Plus, it's economical and versatile, whether it's used as stand alone storage unit, or used to support the roof of a shed or building, like T and L-Sheds.