This is my new obsession for my Golden Retriever! This keeps him happy and occupied for at least an hour! Most bones excetera he goes through in a matter of minutes! I originally purchased in pet store and for two refills it was about $12 which is a little more then I like to spend on something like this, but I was willing to do it because it really keeps him busy. But now I found it in Amazon for like $3 which makes me happy and makes him happy because now I give It to him more often! The only reason I didn't give this product a 5star is because it does kind of make a mess, I find that the residue from him licking it ends up drying on my carpet, so I just have to take a pet stain spray and wipe the carpet after.