Due to the EU TPD regulations which come into effect 20th May 2017, we can no longer sell bottles of e-liquid WITH NICOTINE larger than 10ml. So we now have 30ml packs of 3 x 10ml bottles. Lots of wasteful packaging.
In response to TPD, the industry launched large bottles of ZERO nicotine eliquids to which you can add optional nicotine shots. These are typically 60ml or 120ml shortfill bottles with 50ml or 100ml of flavoured e-liquid, with space for adding 1 or 2 10ml bottles of nicotine liquid (typically 15mg to 20mg nicotine strength). 50ml plus 10ml nicoshot makes 60ml of 3mg nicotine strength e-liquid.