The review of the greencig (G300)did not mention they are very hard to draw on. Less than happy with it. My girlfriend has the very expensive whitecloud cirrus 3. Her "easy draw" atomiser fits like glove on the greencig battery and works. White cloud says you can not refill. I did and it works. Only prob is occasioally it gets real hot on your lips. I imagine maybe because they are not the same mfg. the voltage may be off. I know we are all newbs here but.. anyone ever try a greencig battery with a cirrus 3 atomiser? Is it getting hot because i refilled, or voltage incorrect? Oh well. i guess i will find out when i receive my c3 atomisers pre filled. This is the best of both worlds if i can figure it out. Great draw with a greencig.