What Our Gearhead(R) Experts Are Saying: "I've never worn a down jacket that balances warmth and packability like the Kryos. The Firestorm construction really seals out wind and moisture while keeping the loft of the down high, so it feels warmer than jackets that weigh more. It's the layer I want when I'm carrying as little as possible but still need to be confident on big alpine days." Designed with feedback from elite alpinists pushing routes at 6,000-7,000 meters, the Mountain Equipment Kryos Jacket is built to thrive in some of the world's harshest environments. By combining ultralight packability with serious warmth and protection, it gives us the confidence to commit when margins are thin. The Firestorm construction pairs a Drilite Loft shell with hybrid baffling, dramatically reducing heat loss while keeping weight and bulk to a minimum. Inside, 234g of 800-fill goose down provides insulation optimized baffle by baffle for maximum efficiency. A halo-style neck collar helps seal warmth where we lose it most, while the Super Alpine HC Hood fits comfortably over a helmet or layers of protection. Even with its high-loft insulation, the Kryos remains slim and mobile enough to climb and second long pitches without feeling cumbersome. Thoughtful alpine-ready details finish the build: multiple inner and outer pockets for essentials, a two-way YKK zip with offset baffle, elastic cuffs for glove use, and dual hem drawcords for sealing out gusts. Lightweight enough to pack small but protective enough for modern alpine test pieces, the Kryos sets a new standard for high-altitude insulation.