Welded construction with 1-5/16″ OD tubular dividers on a base of square tubing and angle iron that includes lag down holes and keeps stored materials up off the floor. Storage bays (4 total) are 7″ wide with 1500 lbs. capacity at each opening. Rack comes with (3) Upright Dividers: 27″, 36″, and 42″ high.