All cartridges come pre-loaded with removable poli-fiber core! (This stores your "E-Liquid" inside the cartridge.)
The cartridge is the mouth piece that covers the atomizer. Both the M4 and the 510 have a poli-fiber that can be 'filled' with ULTRApure e-liquid for longer lasting vape, or the poli-fiber can be removed for 'direct dripping'.
Never have to roll down the window of your car in the freezing winter to smoke again! The vapor from these is not toxic and actually has a pleasant sweet smell that your passengers will not object to!
