At the base of the pod is a child resistant lock. This secures the coil in place and prevents it from being removed without being unlocked. E-liquid can be added to the pod through the side filling port. Remove the rubber seal to access the filling port. The SMOK nord PRO coils designed to be used with this pod come in 0.6ohm and 0.9ohm resistances. These make this pod suitable for mouth-to-lung vapers when using the 0.9ohm coil and restricted direct-lung vaping with the 0.6ohm resistance.