| Product Review: The warm, lightweight single boot La Sportiva K4S utilize synthetic uppers and Thinsulate insulation for dependable warmth on Denali and other cold-weather destinations. A synthetic industrial fabric upper seals out every drop of wetness. Thinsulate-PTFE layer warms the foot to the nth degree and a carbon fiber honeycomb insole adds a layer of insulation above the cold, snowy or icy sub-surface. The stiff Vibram sole is step-in compatible, lining it up perfectly for everything from winter mountaineering and technical mixed routes to waterfall ice. |