Combining ultralight elements of Scarpa's Alien race boots with a more versatile, backcountry-oriented design, the all-new F1 LT is the brand's lightest weight alpine touring boot, optimized for high-mileage missions, ambitious traverses, and technical ski mountaineering descents. Carbon Grilamid® LFT shell & cuff delivers incredible power to weight ratio 3D Lambda Torsion Frame increases lateral stability and downhill performance Speed Lock ski walk mechanism is strong, precise and easy to use Boa® Fit System for a fast and secure fit Waterproof gaiter system provides total snow protection New Zeppa increases ramp angle by 3.5° Weight Reference : 990g; 2lb 2.9oz (1/2 pair size 27.0) Liner : Intuition® Cross Fit Tour LT Last : 100mm Outsole : Vibram® UFO RS Shell : Carbon Grilamid® LFT Cuff : Carbon Grilamid® LFT Flex : 100 Forward Lean : 9º / 11º / 13º +/- 2º Range of Motion : 72º Ski/Walk Mode : Speed Lock LT Closure : 1 Buckle + Boa® Fit System Binding System : Tech