My collie loves these, I don't allow him them at home as the flash wouldn't last long and I'm Not sure how they would withstand chewing. but for walks and fetch at night they are great. The balls bounce quite high which he loves and we don't lose them at night which I love! We are on our 4th now will continue to replace as they wear out but each one lasts a good 12 weeks with almost daily use.
I brought 2 of these for my 5 month old collie puppy. They are great with the flashing lights and I had high expectations. Unfortunately in less than a minute he had broken the first one. At the bottom of the ball there is a small circle insert where the lights are placed in. The seal is incredibly weak. I couldn't be more disappointed! I would not recommend to anyone I'm afraid. Great idea, poor application.