We crafted this cool-weather running vest using new WINDSTOPPER(R) by GORE-TEX LABS fabric and PrimaLoft(R) Active Evolve insulation. The result is an optimal balance of protection, warmth, and freedom of movement. It combines a windproof yet breathable barrier with insulation that adjusts to your effort, giving you more protection when running at a slower pace, while refreshing the buffered air on higher tempo runs when your body heat rises. Designed for adaptable comfort and protection on cold-weather runs. Next-generation WINDSTOPPER(R) ePE membrane and active thermal insulation make it an ultra-functional, windproof and breathable vest that offers warmth without unnecessary bulk. ePE WINDSTOPPER(R) Liner by GORE-TEX LABS Airpermeable face fabric PrimaLoft(R) Active Evolve Insulation Adaptive thermal insulation Recycled Lightweight Nylon Woven Totally windproof Reliably breathable. GOREWEAR CONCURVE WINDSTOPPER(R) Insulated Running Vest Men's in Black | XS | Slim fit | Windproof