Tough STRUCTURAL PLASTICS Dura-Shelf All-Plastic Industrial Shelving with Fixed Shelves stores practically anything including chemicals and corrosives. Sets up quickly without tools. Start with 2-shelf base unit and attach 1-shelf add-on units to reach desired height. 24"H posts snap in place via a locking collar system. Fixed polyethylene open grid shelves promote air circulation, prevent dust buildup and allow liquids to flow through.