Antler bars and Stag bars are the same, just different company. They are brilliant for puppies and are perfectly safe. Chewing releases, feel good chemicals from the brain and this uses up energy. They last a very long time, we've only just replaced Harry's and he's had that one for 7 months. There are no additives or preservatives. Make sure you get you smallest one though for your pup you don't want to overwhelm him. Because they are natural they will come in different shapes and sizes. After a while soak it in cold water in the fridge overnight and this will help the marrow come out. Don't hold the stag bar for him let him work it out for his self.