The Aspire Revvo Tank brings a truly innovative design with the ARC (Aspire Radial Coil). The Aspire Radial Coil resembles a 'stove-top' coil which provides a massive increase in surface area compared to traditional replacement coils. With the extra surface area comes impressive flavor and great vapor production. Aspire has also made refilling easier than ever by incorporating a spring loaded fill port just below the mouthpiece that can be used with almost any bottle. To top it all off, a silicone cap is included that can be used to cover both the mouthpiece and all three airflow slots to keep dirt out while traveling.