The Wismec Reuleaux RX2 20700 is the latest in the RX line. The first thing you'll notice is that the RX2 uses the latest in vaping battery technology, the 20700 cell. Offering a higher amp limit and larger capacity than a standard 18650 means that the RX2 will give all-day battery life even at high wattage! Fear not though, the RX2 comes with battery sleeves that allow the use of 18650 batteries with no loss in functionality. Apart from the new battery size and the clean, sliding lock battery compartment, everything else that's so great about the existing RX line of products is the same with the new RX!