I am totally amazed by this toy. My year old Boston Terrier chews through everything, even the large sized black Kong toys. I found this toy and decided to try one more time with a chew toy (I had all but given up on finding something besides sterilized bones that would endure her chewing). It worked! So far we have had it for 4 months and she has only left a few teeth marks in it. It is her favorite toy and she even knows what to get when I say "green bone." If you have a Boston, you need to get one of these! It has saved me money and has saved my shoes.