The tobacco free electronic version of the conventional cigarette was the first of its kind e-cigarette. These looked like the conventional cigarette but instead contained a battery, coil and cartridge filled with e-juice. As time went by this version was upgraded to one which had a rechargeable battery and a replaceable cartridge. Users could vary the amount of nicotine intake depending on the cartomizer, e-juice and battery being put to use. This primarily was how the first generation of electronic cigarettes was.