When we're embarking on multi-day trips high above the tree line, with all sorts of technical terrain between us and our destination, we wear the Lowa Alpine Expert II GTX Mountaineering Boot to handle everything the mountains throw our way. Weather can change quickly when we're at high altitudes, and the PrimaLoft insulation ensures our toes stay toasty when the temperature suddenly plummets and we find ourselves caught in a squall. The GORE-TEX membrane delivers plenty of weatherproof protection, keeping our feet dry as the snow piles up, and the durable leather uppers stand up to scrapes with rocks and ice. The boots are made with a carbon shank to provide incredible stability, and the DuraPU midsole cushions our step so we can spend long hours on our feet pushing toward the summit. The boots are compatible with automatic crampons so we can cross icy glaciers, and the Fit Wing design offers flexibility around our ankles for backpacking.