I know what your thinking oh great another cell phone commercial. (Not at all) For the last year I have doing a test on my dog Sherwood to see the durability of these beef bones that I recommend to almost anyone who has a dog with chewing problems. So the two bones on the left are 9 inches and only have the divets out of them after a YEAR. The other two are about 4-5 inches and have been chewed on the last 8 months by my dog. On average my dog will gnaw at these bones for at least 4-5 hours. So as you can see this is the reason I recommend these bones. You could have a Jaws of life chew on these and they would still last a while. These are great because I can wash these in hot water to get the dirt off or caked in Peanut butter. These can be stuffed with peanut butter, cheese whiz, wet dog food, pretty much anything that you can shove in it. Also to get the longest use out of the things you stuff it with is to freeze it. If you use these let me know what you think.