The High Grade is an excellent choice for those who want a natural fiber, cold weather base layer that will perform remarkably well at retaining heat, even when wet. Merino wool is known for its exceptionally soft characteristics, is naturally breathable and extremely efficient at regulating body temperature due to its great warmth-to-weight ratio. This base layer is ideally suited for pairing with our cold weather and thermal outerwear for defense against the harsh cold and winter conditions, and temperatures between 30° - 60° F.