An electronic cigarette (e-cig or e-cigarette), electronic vaping device, personal vaporizer (vapouriser) (PV), digital vapor (vapour) device or (not to be confused with smoke-free cigarettes) may be a powered device that simulates tobacco smoking. It usually uses a part referred to a an atomizer (atomiser), that vaporizes a liquid. Usually the liquid is a mix of propylene glycol (PG), vegetable glycerin (VG), nicotine and flavorings. Certain electronic look like cigarettes or cigars, whereas other are metal tubes housing a battery, button switch and connection (usually 510 connection) or a box shaped enclosure housing a power control board (PCB) and other components. Battery sizes vary from 14500, 18350, 18490, 18500, 18650 and 26650. Liquid is heated up by the atomizer producing vapour which in turn is inhaled (vaped) vape.