It’s very important to get a safe wheel. No wheels you can find in a pet store is safe for gliders, for various reasons. It’s best to choose one of these wheels below, as they’ve all been created just for gliders and have been tested thoroughly for safety.
Be aware of homemade wheels, they make look similar to these and claim to be safe, but they could very well fall apart during use and injure your glider, or wore.
My Glider Wheels and More
http://www.spinzoneglobal.com/Runab... (Safe version of a hamster ball)
Custom Choice Cruiser
http://cccruiser.com/ (Unique wheels with bounce)