The kit includes one 54" wide tire slat assembly and two tube holders. Purchase columns and 22" arms separately. Included tube holders are mounted to the end of the 22" arms to hold 1 3/8" diameter steel tubes (not included). This tubing is economically available at any Home Depot or Lowes (referred to as 1 3/8" fence top rail). 54" assemblies can be added to extend the full length of the container. Mounting hardware included. Patent Pending.