I bought two of these chairs. The first, for my mother, I found easy to ride and very comfortable. I bought one for myself, suddenly, a few weeks later. Unfortunately, after a few months (3), I found a kind of cottage effect around the axis. Looking more closely, the central sheath, white plastic, metal separates létui (black) and completely out. So what causes a huge instability in the seat! I had to get off the chair to the lowest to avoid the risk of falling. I obviously first contact the seller for an explanation, but after several weeks of silence, I have to get used to the idea: there is no response from the service of the seller! So I recommend, despite the comfort of the chair itself ...