If you buy one used, beware. I bought mine about 3 yrs ago and it was quite wobbly and the wooden bar slides out of the side brackets rather easily. (IMO) It spins around too which feels very awkward when I am trying to balance on it. After hearing so many raves here about how wonderful and sturdy it is, I called CS to see if mine might be defective.
Well, it's not considered "defective" but they did say that they are made differently now, and there is a screw that holds the bar in place. They tried to explain to me how to fix mine, but there is no hole in the metal base to put the screw in, and I am afraid that if I tried to drill a hole in the bar I will end up ruining it. I realize I bought it a long time ago but all together I spent about $250 on this thing. I shouldn't have to 'fix' it. They obviously realized that it was built poorly or they wouldn't have updated it. IMO, it serves its purpose but the price is NOT justified.