No one spends more hours on cold mountainsides than Search and Mountain Rescue Teams. That's why we developed this extremely protective jacket together with their insight. It’s extremely protective with a superior warmth-to-weight ratio for great packability. We used innovative insulation technology -- Lifaloft™ sheet insulation in combination with PrimaLoft® Gold fiber balls and a conductive graphene lining -- to achieve superior warmth. The warmth is distributed strategically via optimized body mapping. As always, we added the weatherproofing you need to stay dry as well as warm. The jacket uses our innovative Lifa Infinity™ hydrophobic fabric, the next level of waterproof/breathable technology. This is a certified bluesign® product.