TF-N2 Nickel 200 Standard Core and TF-N2 Nickel 200 Air Core are newest TFV4 coil heads of SMOK. They have different features because of using different techniques. Inside the Standard Core, all airflow will go through the heating coils, and become warm vapor.  The Air Core with more air holes, in which some airflow will not go through the heating coils, thus producing half cold and half warm vapor for better flavor. New patented TF-N2 Coil are also perfectly for work with the SMOK X CUBE II temperature-control mod. There are also other 4 kinds of type coil head coming soon.