The Koala rubber coated T pipe has a front air jet cap which burns contents much more fully and evenly than all other models. It lets just enough air in with the flame so that coughing is dramatically minimized! The unique and easy to change cartridge/bowl inside the bowl allows you to pack 2 bowls and just switch them out. The extra bowl has a silicone cap as a spare. The pipe cleans much more easily with a cartridge/bowl.