All welded prime cold rolled steel. Gray powder coated finish is rust and acid resistant. 4 fixed dividers per shelf form (40) 13" width by 3-3/8" height by 7-1/2" depth permanent compartments. Optional dividers allow the creation of up to 16 compartments per shelf. Shelf capacity is 60lbs (evenly distributed). Easy assembly using hardware provided. 600lbs Capacity. Measures 17" diameter by 41-3/8" height.