What Our Gearhead(R) Experts Are Saying: "This is the warmest and lightest high-altitude boot I've used. The dual BOA system is easy to adjust with gloves on, and the removable liners are key for staying dry and warm at altitude. It's everything I want for big objectives in extreme cold without weighing me down on the ascent." At the top of the world, gear failure isn't an option. That's why we trust the La Sportiva Olympus Mons S Mountaineering Boot when it's time to venture into the most extreme alpine environments on Earth. Designed for 8,000-meter peaks, polar expeditions, and deep-winter alpine missions, this double boot system maximizes warmth while minimizing weight. Its futuristic construction integrates a Vibram(R) Litebase sole and MorFlex(R) expanded EVA for insulated, abrasion-resistant grip without compromising agility on steep ground. The fully integrated Dual BOA(R) closure system allows for fine-tuned fit adjustment even while wearing gloves, separating tension between the forefoot and cuff for a truly secure feel. The heat-reflective outer shell, built with stretch Cordura(R) and thermo-reflective aluminum layers, delivers unparalleled insulation, while double PE/EVA thermal booties and a 3mm carbon honeycomb footbed ensure warmth and dryness through bitter cold. With compatibility for a wide range of crampon systems and a Corner Zip(TM) design that simplifies transitions, the Olympus Mons S is a pinnacle-level boot built to thrive where few dare to go.