9 Ÿ Ÿ 2 spare plastic connectors are included in each parcel. If you have purchased 2 identical shoe racks, you can use the spare connectors to stack them together; if you have purchased 1 shoe rack only, please keep the spare connectors for future use. You can buy another of this 5-tier rack and stack it with the one you already have for added storage; in this case, please note that antitoppling devices are required for extra stability.