The SMOK RPM 2 Empty Pod is specially designed for SMOK RPM 2 Pod Kit. And the SMOK RPM 2 Empty Pod comes with two types pod for your selection. The 2ml RPM Pod is compatible with SMOK RMP Coil, and the 2ml RPM 2 Pod is compatible with SMOK RPM 2 Coil. In addition, the RPM 2 Pod features a large and ergonomic mouthpiece with an oval-shaped aperture of 9.5×5.6mm, allowing for more airflow and inhalation. Plus the visible juice level window, you can clearly see the e liquid level.