This assembled commercial grade expandable steel crossed frame on front and back locks into wood. Wine rack is very sturdy; keeps its shape and will not wobble. Neck label protectors included. Beautiful maple finish. Modular Expansion Options (Sold separately) The Final Touch Wine Racks are modular so you can easily increase your cellar capacity. One expansion kit will connect two wine racks. Connect two, three or more racks for a custom wine cellar. Grow your cellar one rack at a time as you grow your wine collection.