Environmental friendly materialAll workmanship is non-toxic, safe and environmentally friendly. All parts are rounded and smooth, avoiding hurting your little creature. Avoid noise Sports wheel of quiet running, super mute, hamsters play at night, does not affect the owner's sleep. Fun Play This is a great wheel roller for your pet hamster to exercise or have fun when you are outside, let your pet hamster have fun and exercise! Safe for your petNon-slip design, safe for the hamster.Exercise and have fun to gnaw on your hamster. Suitable for small animals Nice pet toy for hamster, chinchillas, guinea pig and other small animals. Warning: Not suitable for children under 14 years old. Use under adult supervision Caution:Use under adult supervision