VOOPOO PNP Pod Tank is a new concept created. With 510 base at the bottom of the Drag X Cartridge & Drag S Cartridge that fit for Drag X and Drag S kit. The tank can hold up to 4.5ml of your favorite juice, and refill the juice from the bottom of the Pod by twisting 510 base. Removed with just one hand, and you'll experience a simpler and cleaner way of filling oil. It comes in two forms: on its own, it's the perfect partner for Drag X and Drag S. It's perfect for any 510 thread devices you want. PNP Pod Tank can flexibly switch between POD and TANK.