The lower hole in part c of the left back rest is too small. The screw will not even go into the hole like the other 3. Thus you cannot countersink that screw and it won't go into the cushion back so that you can make it sturdy. When I called y'all you didn't act very concerned and told me that I would ruin the warranty. So I called Wayfair and they are requesting that part from y'all and I hope to get it and hope that the hole is drilled bigger and hope it is not a manufacturing problem that you have created yourselves yourself. c service