round Hamster wheel (very thin)

Hi,

I designed a hamster wheel, which is very very
filigree, but has very low mass inertia ;) :-D

My most attention layed on:
It should be closed on one side to not break any hamster feet.
It should be round like a bowl for keeping the hamster inside while it is running.
It should have some rips to avoid slip.
It should be mountable on a 608 zz bearing
It should be smaller than regular wheels
It should be so lightweight, that the hamster can stop up anytime without getting thrown t