If it's new in package how are you not sending the cartridge, that is in the package? I am not trying to be rude, but when you say new in package you normally don't break up the package!
I'm sorry. I might be confused, this is new in package and comes with everything in the package. I thought a cartridge is the nicotine. It doesn't come with nicotine.
You can use different liquids. Just make sure you clean it good before changing the liquids. They have different nicotine levels as well so if you are a heavy smoker you could have a higher level nicotine.
I know it doesn't have a flavor, but other than that, I am not that clear how they work! Lol I do not smoke and accidentally bought this on eBay thinking it was something else. The instructions say how to use it. :)