Color sent at randomDiameter 7cmProduct description:1. Principle: High-tech products， non-squeezing vocal， do not install the battery， because the internal magnetic field and a ball， when the dog rolling ball， the ball cutting magnetic field lines of magnetic power， thus sound.2. Because of the above principle， only the magnetic ball cutting magnetic field lines， fast enough， big enough electricity to sound. So， the dog will find different directions， at different speeds when magnetic ball rolling， the sound will be different sizes， too slow may also not sound， no sound is some rolling direction， so that the dog thought， will never be bored， but also development of intelligence --- become a clever little dog!3. No dog can be a delicious snack Zuohuaibuluan， stuffed some small snacks in the ball， pay attention snack volume to the right， not too small， the dogs can easily eat， can not be too large to squeeze inside ， how to pull the dog can not eat. While also showing a little ball on the outside， the fragrance to lure the dog， Youchang with the sweetness， it will concentrate on the ball inside the snack dig a little bit!4. You can sound. Pets are like chasing play5. There are special holes， so that food leak. Can be used as Pet Feeder6. plastic products， may have a slight plastic smell on the air circulation around the time it will be dispersed， it does not affect use.