I received this set last Christmas as a gift and used them several times over this past year. I mainly love this bag, not so much for the bottles, but for the bag itself.

After a horrible mishap a few years ago, a pilot friend warned me to never use the flip top lids because they invariably leak . . .and only fill the bottles half full.  When the pressure drops, the liquid will expand.  Either it must leak through the lid, or explode, but its going to go somewhere.