HAPPATIO 10' X 13' Outdoor Pergola with Sling Retractable Canopy and Woodgrain Aluminum Frame, Arched Pergola for Patio, Deck, Backyard, GardenHigh Quality Materials: The pergola canopy is made of improved yarn dyed fabric, more durable, UVproof, two years of colorfastness. If you want to secure the pergola to the deck or concrete, we recommend using the ground nails or expansion screws (both included with your pergola set) on the four bottom posts of your pergola. Sturdy steel wood like structure: Sturdy and durable, the whole frame is made of powder coated steel. The pergola has a uniquely