Review on 4-1/2-Inch Wire Mesh Mouse Wheel Toy for Small Animals by Prevue Pet Products - Colors Vary by Sean Patel

Bought one for my daughter's two mice. Then I had to buy another one because the mice just liked the wheel and as they grew one wasn't enough. The wheels seem safe - I've seen mice leap and jump, roll upside down etc and no injuries so far. The wheels are fairly quiet - a little greasing is needed from time to time, but nothing major. Very happy with the wheels. Please Note: We have an aquarium so we just lay them on the floor rather than trying to hang them.