Smokeless cigarettes look exactly like a normal cigarette and consist of 3 main components. The cartridge which which acts as the e-liquid reservoir, the atomizer which heats and vaporizes the e liquid for inhalation and the battery which powers the unit. All parts easily disassemble and are replaceable for just a few dollars. The life span of each part depends on the smoker but you can expect to get about 1-2 days per cartridge (replacement cost $1), 6 months to a year for an atomizer (replacement cost $8) and 6 months to a year for a rechargeable battery (replacement cost $10). I also want to mention that replacing cartridges is the easiest way to refill your ecig but you will save the most money by purchasing e-liquid re-filling your cartridge.
Smoke free cigarettes are either automatic or manually operated. With automatic models, when the user takes a draw through the ecig, the atomizer automatically senses the air flow and heats a small amount of e-liquid for inhalation. Manually operated models require the push of a button to activate the atomizer. Most users prefer the auto operated type as the manual style can be accidentally operated while carrying. Both models are made to shut off the unit if temperatures become too high so there is no danger of burning or fire. Inadvertently turning on the manual model will simply wear out the battery prematurely.
There are literally hundreds of sellers of electronic cigarettes on the internet. The problem is that only a small fraction of them sell authentic products designed to last a lifetime. The rest sell cheaply made knock-offs that have a life expectancy of 1-3 months. The cheapies look exactly like the originals but you can usually tell the fakes by their unusually low price.
Another thing potential buyers need to watch out for are the electric cigarette vendors who give away free e-cigs. These vendors will want to enroll you in their auto-ship program where they re-ship you over priced e-juice every month. You should NEVER sign up for any type of auto-refill program. Find a reputable seller and stick with them. This is the safest way to purchase your first starter kit and all of your replacement parts.
E-Cigarette Safer Than Tobacco
FDA VS E-Cigarette
Smoking And The Environment