The structure is mostly made of aluminum, with what seems like very poor QA process. 3 of the 4 support columns arrived with significant dents that could result in the structure collapsing under strong winds. Holes for screws are poorly machined, sometimes off by almost 1/2 inch from where they should be (see photo). Luckily Wayfair support was great, once they found out about the problem, they sent a new set (which wasn't without problems either - but between 2 sets we managed to assemble a complete Gazebo). Even then, however, the mounts for metal poles that hold the cloth in place are made out of flimsy plastic, almost as if the manufacturer intentionally wants these to break after first few months of use. Also, the last pole can't even be mounted to the plastic mount located in the center because doing so would require us to cut the cloth that is attached to it, so the pole is only supported by the other 2 mounts and will likely break even sooner.