These are a great 'babysitter' for our active Border Collies.  They last so long, and keep them occupied.  Nylabone DURA are the only type I get and love that they make the DURAs in such great styles.  Each of the three dinosaurs is unique.  I only wish we would be able to select a specific dinosaur from the three styles, but -- we get what we get.  And, although that is disappointing to me, perhaps not that much to our dogs.  (However, if I order 2 or 3, I seem to get all the same style.  Now that would be nice if I got one of each. Hint, hint.)  Otherwise, love these!!