The cost-effective solution when you’re looking for heavy duty metal storage racks to handle hand-loaded materials. Add-On Unit includes 1 upright frame and 3 shelf levels. These bulk storage racks offer almost twice the capacity per level as standard bulk racks thanks to the formed step beam frame. Beams attach to frame in seconds without tools. The 14-gauge upright steel frame measure 1-3/4″ x 1-3/4″ and allows beam adjustment easily on 2″ centers. Heavy-duty 12-gauge beam connectors have 3 hooks at each end for positive connection. 18″ deep models do not include deck supports. Welded base plates on 18″D racks accept optional caster kit for mobility. Casters include 5″ x 1-1/4″ non-marring polyurethane wheels (2 swivel, 2 rigid) and offer 1,000 lb. capacity.