TFA flavour concentrates are Naturally and Artificially Flavoured. Made in the USA by The Perfumers Apprentice& Rebottled by Vapour Depot in the UK. Available Sizes: 10ml, 30ml, 100ml Recommended Mix (Single Flavour): 2% Recommended Mix (Multiple Flavour Recipe): 1% Requires mixing with Vegetable Glycerin & Propylene Glycol before can be vaped. TFA Koolada Concentrated Flavouring A large range of flavours for use in various applications such as: Baking, Candy-Making, Carbonated water (soda flavours), and many other applications that have fun with flavours!. Koolada is used specifically to give that \"cold\" feeling at the back of the mouth.