This boot begs for abuse again and again. Karakorum used a new tapered 8mm high density Nylon® that provides a smooth flex and protection throughout the boot. This allows for new-matic crampon compatibility and long lasting consistent flex. The 2.8mm Idro-Perwanger leather upper is ideal for water repellency, breathability and durability. A SBR Aircushion sole provides cushion and helps insulate from cold or hot climates. Perfect for light duty mountaineering, heavy hiking and backpacking or various types of outdoor work situations where you need durable support and all-day comfort. IDEAL TERRAIN: general mountaineering and heavy backpacking. WEIGHT: 30.97 oz/ 878 g. LAST: Makalu. UPPER: 2.8mm Idro-Perwanger Roughout Leather/Vibram® rubber rand. Cordura® cuff. LINING: Dry-Best. INSOLE: 8mm high density Nylon® with anti-torsion plate. MIDSOLE: SBR Aircushion. SOLE: Vibram® Couloir. SIZES: 38-48 (half sizes).