It's all plastic, but very rigid and sturdy: no plastic flex at all.It was quick and easy to assemble: no problems at all.The fold up arms are wonderful. Sometimes arms just get in the way; hence, it's excellent to be able to fold them up, out of the way.It's an excellent value for the money in my opinion.Unfortunately, it and I are incompatible with each other. I have a lot of forward curvature in the upper part of my spine due to too many years of sitting stooped over at a computer doing computer programming. The lower, lumbar part of the seatback fits me perfectly, but the upper part of the seatback is curved too far back for me. The headrest is inches behind my head. Also, the minimum tilt tension is slightly too much to suit me. Hence, after an hour or two of sitting in the chair, my back starts to hurt.It fits my spouse perfectly. She loves it. Her head rests against the headrest and everything. And, since I bought it for her to primarily use, it's just right.