It’s made with different Polartec® fabrics to provide optimal thermal performance and comfort. We use the Polartec® Power Grid™ 186 g/m2 (89% recycled polyester, 11% elastane) in the back, stomach area, underarm, and hood because it offers excellent quick-drying and moisture-wicking properties. This patented grid design structure is a way to reduce fabric weight while increasing warmth and compressibility. Open-air channels surrounding each segment of the grid allow easy release of all excess body heat as it builds during activity