The iJust kit by ELeaf comprises of a battery with power of 3000mAh and an atomizer with capacity of 4ml. The iJust one has an integrated battery and a tank with capacity of 2ml. The iJust X comes with an internal tank and a new body design. It has a battery of 3000mAH. The iJust Start Plus comes with a direct output voltage facility, adjustable air flow and a side USB port for charging purposes. The iJustNex Gen is a combination of a 3000mAh battery and a tank with capacity of 2ml. This is a compact but very impressive unit.