4-Shelf Carts have 4 shelves and 4 posts.3-Sided Carts have 4 shelves, 4 posts and enclosure panels.All carts have two 5" swivel casters and two 5" braking casters.SQUARE POST MOBILE UNITS Carts have an overall weight capacity of 1, 200 lbs., evenly distributed.Durable bright plated shelves and posts.Square tubing posts provide extra rigidity for increased weight capacity over round posts units. Shelves are adjustable in 2" increments. All units ship unassembled for compact storage and freight savings. FOB Shipping Point. Use with a stainless steel dolly base if you want to tow it using the PlusPower Tug (see Related Items tab below).