PENCO Rivet-Rite Single-Rivet High-Density Extra-Capacity Shelving is engineered to provide safe, economical storage of virtually any kind of hand-loaded material. Starter and add-on units combine to form economical rows of shelving. Rigid, boltless connection between beams and posts. Designed for units up to 48" wide. Starters and add-on units are all 7'H, have 6 shelves (top and bottom shelves are double-rivet) and assemble easily without tools. Common T-post between units assures additional rigidity. Easy access to contents from all sides. Braces not necessary. Shelves adjust on 1-1/2" centers. Particleboard decking sold separately. Light putty baked-on finish. Optional heavy-duty single-rivet beams available (or make your own custom units using 5', 8', or 10' high uprights). Made in USA.NOTE: Starter includes (4) angle posts. Use 2 for starting a row or unit, use 2 for ending a row or unit. Add-On includes (2) T-posts. Use 2 for joining add-ons to starter or to other add-ons. Combine 36" & 48" wide single-rivet units with wider double-rivet units.NOTE: Assembly is simple. Just insert shelf rivets into adjacent T- or Angle post slots. T- posts are used to add-on extra units. Angle posts form unit’s corners.