And not all places give you the choices, either. One of my favorites doesn't, so I have no idea what it is, but it produces the vapor and 'sensation' I needed to get off cigarettes, so I don't look a gift horse in the mouth. I would assume if you especially like the way a particular company's juice vapes, you could write to them and ask them what percentages they use for future reference when ordering from those that do provide that option. No guarantee that it would have the same qualities you liked in the first juice, but it would be a somewhat less random starting point.