With its Primaloft Eco insulation and Tropozone waterproof breathable fabric, the Sierra Designs Prima Fusion Insulated Jacket is ready to tackle your next high-alpine adventure. The Tropozone 3L fabric features a PU membrane to protect against rain, falling snow, and high-speed winds, while a DWR coating encourages water and melting snow to bead up on the fabrics surface without affecting the garment's overall breathability. Sierra Designs also included a touch of insulation for extra warmth.