The classic pen Advanced! What have they done to them, they literally last about a month now then the cartomizers don’t screw on anymore, so far I’ve returned 4, each one apparently hasn’t arrived ( proof of posting is essential I’ve found!) I’ve still got an old one that’s two years old and works brilliantly, but the new ones are a waste of money, am giving up now and will try another product, but still use the liquids