Short-Fill e-liquids are larger size bottles with no nicotine included (0mg), when purchasing you the have option to add a nicotine shot which will give you 3mg strength when added to 50ml of vape juice, with 100ml short-fill bottles you will add 2 nic shots to get 3mg strength. If your desired strength is 6mg then double the nic shots depending on the e-liquid volume.
Short-Fills are generally available in fruity juicy flavours and come in high a VG formula.