Product description:
The product is small and easy to store, and can be placed anywhere
Suitable for small pets. Pets can run and walk slowly in the roller, providing a kind of fun for pets
The product holder can be placed anywhere, which is convenient for you to play with pets and enhance the relationship with pets

Diameter: 13cm, 15.5cm, 18.5cm, 22cm
13 The inner width of the running wheel is 5 cm
15.5 running wheel inner width 5 cm
18.5 running wheel inner width 6 cm
22 running wheels with an inner width of 8 cm.

Warm Tip : Please be reminded that due lighting effects, monitor's brightness/contrast settings etc,
there could be some slight differences in the colour tone of the website's photo and the actual item.
Item Measure by hand, it could be 1-2cm different,your kind understanding will be much appreciated.