"This is a good wheel, but it's not my favorite. I prefer Wodent Wheels - much safer - and have always used them with my hamsters and my rats. However, I now have gerbils, and the Silent Spinner is the only plastic wheel they won't chew.
This wheel really is virtually silent, and it goes very fast, which they love. They do occasionally slip out of it, though, or even do an unintentional flip out of it, which is dangerous but no more so than all the metal wheels. One of my girls is a crazy fast wheel junkie, so as everybody else says, the yellow connector does break. I have to replace them about every 4-5 months. But that's better than the couple weeks it would take them to chew up any other plastic wheel.
I do wish they made a size between the 6.5" and the 12". 12" is far too big, but full-grown female gerbils *only just* fit in the 6.5" without arching their backs. I'd prefer to have an 8" or 9" for them.
Overall, a good, quiet, reasonably safe choice, with a few drawbacks."