Adjustable in 1-1/2" increments, the shelf levels feature double rivet connections and are center supported for maximum capacity. The steel decking is 22-ga. galvanized sheet steel formed into 6" deep channel parks. Multiple planks are used to meet unit depth. The particleboard decking is 5/8" industrial grade type 1-M-2. Both decks must be center supported and cannot be used on single rivet units.