We were looking for a stable, leichtläufiges, low noise and a sufficiently large impeller for our dwarf and have found this.
I bought it in the size of 28 cm.
At first it was very difficult to move and our dwarf was able to move on its own, it barely.
After my friend has the holes by about 0.5 mm, with a drill, expanded, it is also possible for my dwarf in this wheel to run with ease and he runs and runs and runs. : D
CONCLUSION:
There are of me 4 stars because we had just help out with a small drill bit so that our dwarf may move the wheel alone. Still, I would buy this wheel again and again.