Fever-tree cocktail mixer Indian tonic water in the 4pk is a premium, naturally brewed satisfying drink. By blending subtle botanical flavors with spring water and the highest quality quinine from the fever tree, a delicious natural tonic is born with a uniquely refreshing taste and aroma. There are no artificial flavors, sweeteners or preservatives. Each 4 bottle pack contains 27.2 fl. oz. of premium tonic water.