Lightweight, stiff, and low-profile honeycomb insole for superior insulation Waterproof, breathable, and insulated Gore-Tex membrane for optimal protection Flexible 3D ankle design for enhanced mobility Adjustable tongue for personalized fit Ideal for winter mountaineering, ice climbing, and mixed climbing Crampon compatibility: non-automatic, semi-automatic, and automatic Combining innovative 3D Flex ankle construction and super warm Carbon-Tech honeycomb insole, the Nepal Cube GTX delivers the latest in mixed terrain climbing footwear. This lightweight, technical single boot is ideal for cold-weather climbs on variable terrain.