Amazon カスタマー 5 This is the second wheel I’ve purchased for my hedgehog and just by looking at it, I can tell this is way better than the Sanyo silent wheel, the first wheel I purchased.Compared to the orange Sanko wheel, this wheel has a metal gage in the center so that the wheel is stable and rotates without making noises. The previous wheel I purchased (Sanko wheel) has a plastic core which ended up making noises a year later.Another thing I like about this is that the center of the rim (where the brown and clear plastic part meets) doesn’t have any cracks. My previous wheel had small cracks which was dangerous for small pets since their tiny nails/toes might get stuck in them.Another merit is that there are slits on the back of the wheel. I’m not sure if it will make any difference but it’s suppose to help to make it air resistant. I don’t know if this will make a huge difference, but it does seem like my pet doesn’t struggle to run on this one. It seems like it’s a lot smoother for him while running.Lastly this is about the same or a few hundred yen more expensive than the Sanko silent wheel but this a more effective design. My only regret is not purchasing this the first time