Update:  While I originally loved this product and so did my dogs, I feel the need to update this review.  The Dura Chew Nylabones are incredibly hard, which is what makes them last so long.  However, one of our dogs did crack a tooth recently from chewing on a Dura Chew.  Since then, we have been very hesitant to allow any of our dogs to chew on these as other reviews also state that dogs have cracked teeth.  We have since thrown out all of the Dura Chews that we had.  We are still using the regular Nylabone products (when they aren't made in China), but once those are gone we will not buy any additional products from Nylabone.  We have been buying Whimzees for our dogs for the last two years or so and they are a healthy edible alternative.  They do not last as long because they are edible, but I have the peace of mind in knowing that my dogs are safe with them.  Another healthy alternative would be antlers, which we also give to our dogs and they usually last a long time.