Its no surprise to me that everyone is flocking to buy e cigarettes online because blu is the best electronic cigarette in the market, not only because of its unique flavors, but also because of our industry-exclusive pack. The pack charges your batteries on the go and allows you to carry around 5 cartridges together with two batteries in a high-quality plastic case that is similar to a normal cigarette pack in size. Additionally, our patented cartridge produces more smoke than other electronic cigarettes and provides a more authentic experience that feels and looks like traditional smoking - without the tar and carcinogens.blu cartridges last 130-160 puffs, depending on the smoking habits of the user. One blu cartridge is equal to approximately 15 traditional cigarettes. blu cartridges contain nicotine (in levels of high, medium, low and no nicotine), propylene glycol, tobacco flavoring, and other flavoring ingredients exclusive to blu. These cartridges come in various flavors and nicotine levels to satisfy the needs of a variety of smokers. Propylene glycol is a water-based ingredient found in many health products and medicines. None of the ingredients in the cartridges have been found to be carcinogenic.