Ordered 2 at first few moths ago. Perfect...so I ordered 4 more of them and each ones comes with an Allen key. 3 if them did not fit and lucky one did, which I used for all of them to tighten. Was lucky I didnt order 2 or 3 and left with Allen keys that don't fit and would not be able to fix and the hassle it would have caused me. Also the seat cushion on 3 of them are fine and one of them is really hard. One of the seats squeaks when anyone sits on it.  Not the standard I expect but cannot be bothered to unscrew and pack away to get a refund or replacement.