THIS PRODUCT CONTAINS NICOTINE, WHICH IS A HIGHLY ADDICTIVE SUBSTANCE.
Nic Salt E-liquid the nicotine is present in a slightly different form.
Nicotine is Alkaline and in high concentrations unpleasant to vape. So Benzoic Acid is added to the process to lower the PH (reduce the alkalinity) to make this strength more palatable to vape.
Also this form of nicotine absorbs much quicker.
When smoking a cigarette the nicotine is absorbed quickly and to a high level, whereas with standard nicotine e-liquid this is more gradual. You will probably notice when you chain vape you keep your nicotine level stable.