TFA - Koolada (Flavoring) in The Flavor Apprentice
TFA - Koolada (Flavoring)Item #: FLAV-TFA-KOOLADA
The Flavor Apprentice Koolada - DIY E-Liquid Flavoring
It is also known as "W3" Koolada is used specifically to give that "cold" feeling at the back of the mouth.
It does not really have a 'taste', but it can be used in conjunction with menthol.
try using 4 drops per 4ml of eliquid.