- Fabric: 74% Merino wool, 25% nylon, 1% elastane
- Flat-knit side panel
- Full cushioning
- Flat-knit toe seam
- A stretch arch & ankle brace to keep the sock in position
SmartWool’s Mountaineering Extra Heavy Socks have extra-heavy full-cushioning that keeps your feet warm and dry when you’re mountaineering, ice climbing or multi-day backpacking in cold climates. An arch brace holds the sock in place and adds additional support, while the flat-knit toe seam keeps you comfortable.