What Our Gearhead(R) Experts Are Saying:"This is easily the most advanced midlayer I've ever worn. The 50/50 baffle design dumps heat when I'm climbing fast, but still keeps me warm at high altitudes. t feels like something straight from an alpine dream kit."When our alpine missions call for ultra-efficient performance, we reach for the Summit 50/50 AMK Hoodie. Built for The North Face's elite Advanced Mountain Kit, this hooded jacket blends cutting-edge technologies for climbers and mountaineers pushing limits in the world's harshest environments. With 50/50 baffle construction, the jacket allows warm air to escape while regulating core heat, keeping us comfortable and dry on long vertical pushes. The 1000-fill ProDown insulation delivers powerful loft and warmth without weight, while Spectra ripstop and NANOREFLECT materials add durability and thermal reflection where we need it most. Designed for total movement and pack compatibility, this hoodie includes an articulated fit, climbing-helmet-compatible hood, bonded stretch cuffs with thumbholes, and thoughtful insulation placement in the lower body and forearms. It even packs down into its own ultralight ripstop stuff sack. This is expedition-grade warmth for those who go far and high.