I actually did a video reviewing it and showing how to put it together when they had just come out! Six years ago now. So it's flummoxed me that there is a small gap inside with this current one when I know it shouldn't be there! At the time it was an exciting new thing as the only real choice was wodent wheels or the 12" silent spinner (which was huge and not silent and didn't spin that well) or the trixie wood and plastic ones. This was the first large wheel that easily attached to bars.
Now though, I think I prefer open wheels (for cleaning) and there is more choice - but it's still a great wheel (if no gaps) and hamsters love it - but then hamsters love most big wheels! I thought this was expensive at £25!