The Nautilus is the next generation of tank systems. Made of stainless steel and Pyrex glass, the Nautilus also uses Aspire's new "BVC" (Bottom Vertical Coil) atomizer technology. The Nautilus has an exclusive adjustable airflow design that is revolutionarily. With a simple turn of the lower ring, you have four options to adjust airflow to meet people's different requirements for vaping (airflow adjustable sizes - 1.8mm, 1.4mm, 1.1mm, 0.9mm). With the option of different sized air-ports, it allows the user to produce big clouds of vapor, with a pure and clean taste. With the unique Nautilus four-port system, you can adjust how hard or soft the draw is, how warm or cold the vapor is, and how much vapor is produced. The Nautilus is also very easy to install and refill.