If you've been using a rechargeable electronic cigarette for a while, or you're thinking about making the jump from disposable e cigarettes, knowing about the parts of these devices is essential. Without at least a basic understanding of how to use an ecig or how the devices themselves work, you may end up becoming frustrated with a vapor cigarette that just doesn't work the way you want it to. The good news is that with plenty of vapor cartridges available, you're sure to find something that suits your vaping needs. First, however, you'll need to know about this vital part of the e cigarette, including knowing the difference between a tank and an EGO Mega cartomizer. Here's a rundown of what you need to know about buying cartridges for your vapor cigarettes: Type of Cartridge Not all vapor cartridges are created equally, and some, in fact, aren't even called cartridges at all. A cartridge, by definition, is just the space in the electronic cigarette where the e liquid goes. Yet there are also cartomizers, which combine cartridge and atomizer to both store and heat up the e liquid. Some types of cartridges and cartomizers can only be used with particular batteries or other parts. The EGO mega cartomizer, for instance, is only for use with an EGO battery. At Vapor4Life, the EGO Batteries and Cartomizers are custom-built with an 808 thread in order to improve airflow and performance. Tanks either contain single or dual coil heating elements to create vapor from e liquid. Other cartomizers and tanks will only fit together with certain types of batteries and mouthpieces. If you're not sure what you need, check with the manufacturer or supplier. Number of Uses Over time, the e liquid that is used inside of vapor cartridges can tend to "gunk up" the works, thus making the cartridge, cartomizer, or tank lose its effectiveness. When you go to order a cartridge, you'll see that it's only for use a certain number of times before the liquid inside tends to taste burnt or bland. Some cartridges can only be refilled five or six times, like the EGO mega cartomizer. Others, however, can last for a dozen or more uses, such as the Smileomizer and various types of tanks. Keep in mind that no matter which kind of cartridge you buy it will need replacing eventually, so consider buying in bulk, too. Blanks or Refills Some e cigarette users prefer to refill their own cartridges, known as blanks, so they can experiment with the many vaping flavors for sale. As of today, there are around 7,000 flavors on the market, with at least 250 more being introduced each month. These also come with adjustable nicotine concentrations, ranging from zero to low for casual users (between 0% and 0.6% or 0.8% mg/mL) and extra strength amounts for former heavy smokers (about 2.4% to 3.6% mg/mL). If you feel like that's too much work, however, you can buy pre-filled cartridges to make vaping even easier. What do you prefer to use with your vapor cigarette? Tell us in the comments.