A Combat Healing Flask is an item that cannot be put into your vault or traded. It restores 5% of your max HP (Hit Points) for 20 seconds. In addition it can only be used in certain places (Goldenia Rainforest, Dragonspine Battlegrounds, and Sengolia Battlegrounds). You can get it also by exchanging 10 Bronze Honor Badge for 10 pieces. You can buy them in the Item Shop for 25 crystal. You could also win them from the Dragon Hunt.