There are two(2) types of electronic cigarette cartridges out there on the market right now. Before you go grab yourself a new electronic cig kit educate yourself on what options you have.
The One(1) Piece Cartridge
Simple, the filter which holds the liquid nicotine and the atomizer are all in one piece (highlighted in red in the photo below). You find this setup on two piece electronic cig kits, not to be confused with a two piece cartridge. This style is just a battery and a cartridge with a built in atomizer.
The advantages to these are that they are convient and you don’t have to worry about the coil in the atomizer burning out. The down side is these types of electronic cigs are more expensive since each filter has its own built in atomizer. This also give manufactures a way to differentiate their product by having different size male and female ends so pieces ARE NOT interchangeable amongst brands.
It should be noted the One Piece Cartridge can be either the male or female end. Meaning the battery either screws into the cartridge or the cartridge screws into the battery. The example below is a male ended One Piece Cartridge.
The Two(2) Piece Cartridge
Unlike the three piece electronic cig with a Two Piece Cartridge (pictured below in blue) is actually three separate components. The battery, atomizer and cartridge. The main difference in this style is the cartridge and atomizer are not one piece.
Since the atomizer screws onto the battery the filter just pops on and off. The advantage is that they are less bulky to carry extras around and cheaper to produce and cheaper to buy. There are no male or female ends you just slide the nicotine cartridge onto the atomizer. The downside is you are stuck with only one atomizer and risk burning the coil out. Usually these styles have better built coils as the have to last but you still risk potentially having to repair the coil or just get a new one.
Either way you go, now when you go to choose a electronic cigarette kit you know what you are getting.