I don't like this product at all. They don't last long against big chewers, my vet suggests that they can cause "binding up" in the intestines as the product is "gummy" and can contribute to many unnecessary medical issues for our dogs.
I really like this tool, when I think I am finished grooming my dogs I can pull out the Furminator and get a ton more hair. I have gotten so much hair even from my guys with short coats. However, I have seen the "knock offs" at a much better price and they tend to work just as well.