The Nautilus 2S is a 2ml capacity tank, designed to be filled from the top. Unscrew the top cap anti-clockwise a few turns, place your thumb on the top cap above the indicator spot and push away from you, this will reveal the filling slot. It comes with two coils: a 0.4ohm BVC coil and a 1.8ohm coil. The 0.4ohm coil is designed for more vapor production, the 1.8ohm is designed for a smoother hit. It comes with 10 x O Rings and an extra drip tip. The longer drip is to provide more of a mouth to lung hit, while the shorter one is designed for straight to the lung hit. It features bottom adjustable airflow.