As you can see from the above illustration the cartomizer is a cartridge and atomizer head in one unit. Again these these are sold in different sizes and resistances:
Low – 1.5-2.0 ohms
Standard 2.5-3.0 ohms
High – above 3.0 ohms
These are made up of a chamber holding the e-juice and a batting material around the atomizer head which wicks up the eliquid for vaporization.
These can either be top or bottom coil type (the illustration above shows a a top coil). Cartomizers can be refilled but do have a limited lifespan, usually about 5-7 refills and 1 cartomizer contains the equivalent of about 10 analogue cigarettes. Clearomizers are basically cartomizers that are clear so you can see how much juice you have left, you will find that the 2 piece electronic cigarettes in Canada will be equipped with Health Canada compliant cartomizers and do not contain nicotine thus avoiding nicotine addiction
This system places the cartomizer within a tank and the tank is filled with e-liquid. This makes topping up easier and gives a visual indication of juice content, similar to clearomizers. Tank sizes vary but usually a small tank holds about 3ml of juice and a large holds 5 ml.
With tank systems a hole needs to be punched at the bottom of the cartomizer in order for the e-liquid to get inside. This can be achieved by using a nail, hammer and a vice or a dedicated cartomizer punch tool or even better you can purchase pre-punched cartomizers. Some have one whole while others have two which greatly affects the flow of e-juice to the cartomizer. The problem with the pre-punched cartomizers is that some people find the holes to be too small so they end up opening them up a little themselves