Maximize your storage capacity with overhead track shelving. Overhead track system allow more storage units to fit in a defined space than a traditional shelving setup. A movable, open aisle allows full access to each entire shelving unit thus eliminating hard to reach or "dead" spaces. Includes four 74" high mobile posts, four casters, donut bumpers, guide rollers, and other hardware to assemble a mobile unit. Shelves are sold separately. 21" Mobile Kit.