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I bought two and accidentally punctured the first one when I attempted to inflate it. The second one has held up decently well. If you're planning on doing anything rough with this, I don't think it will last. I use it with a Bosu ball for balance exercises and if it lasts a year I'll be happy. In the future I'll order a second bosu.
I ordered the green ball for a seat for a 1st grade student based on the reviews I read. There is no way that ball is big enough to use at a small desk. I then ordered the blue ball! It isn’t much bigger in size! If you are looking for a ball seat at a small table for 5-7 year olds, these won’t work! They are sturdy but just entirely too small!