Important part was not (small barrel nut) shipped with the product.  This part stabilizes the bookshelf.  I have been to all the hardware stores in this city to try to purchase one.  The particular size needed is not in the stores.  Just waited on the phone for about 15 minutes to speak to someone.  Wait time is long.  Please contact me because I can’t use the product without the necessary part.  This is a birthday gift for my 13 year old grandson!!!!!