Review of Koolada 10% PG Flavor-TFA:

Koolada adds cool sensation to your mix without introducing mint or menthol flavor.  Very Potent, so small amounts can have a big effect on your end result.  0.5% adds "cool"  1.0% adds "cold"  1.5% is downright "icy"  and 2.0% is "Frozen Tundra Cold"