Formed l-angle steel posts , e-coated ( black), 2.000” x 2.000” x 0.1875” thickness 50.8 mm x 50.8 mm x 4.750mm thickness Cold rolled steel, 11 gauge ( 0.125” thick, 3.175mm) 5.000” ( 127 mm) diameter poly urethane casters, 2 swivel with brakes and 2 rigid, grease nipple for ease movement on casters, best suitable for warehouse and industry floors Top and middle shelves can be installed lip up or down