A technical lightweight double boot for cold environments. Inner boot: removable microperforated, thermoformable polyethylene. Outer: PU-Tech synthetic/polyurethane-coated leatherette; thermal insulating closed-cell foam. * Fast Lacing System designed for one-handed closure, even with gloves. TPU midsole with variable thickness suitable for crampons front/back. Dual-density Micropore EVA midsole with variable thickness. * 5 mm thermal-structure carbon fiber insole with aluminum insulation. Vibram Montagna outsole for solid traction. Outer boot features water-repellent Lorica coating, Vibram rand, molded TPU ankle/backstay reinforcement. * Outer boot insulating foam lined with thermoreflective aluminum facing/antiabrasion flocking. Inner boot features water-repellent Lorica coating and minimal outsole plate for durability. Instep Overlap technology allows an easy, comfortable, and precise fit. * Very light: a pair size 42 weighs only 2300 g.