Hi everyone, what kinds of E-Cigarette are you using ? before I used the RN4081 and the DSE901, they are having tobacco tar, and poor quality. Every time I would dirty my hands when I exchange the cartridge,that is very annoying. But recently Im using LT-V9 instead of the RN4081 and the DSE901.That is because it is very easy to exchange cartridge,and will not dirty my hands,the most important point is that LT-V9 has bulky smoke.It is composed of two parts.