Whether we are hiking through frozen tundras or just our for a casual winter hike, We trust the Merrell Coldpack 3 Thermo Mid Zip WP Boot for its premium construction, waterproof and insulated design, and aggressive rubber outsole. 200 grams of synthetic insulation keeps our feet warm, while a SOLARCORE aerogel insole blocks out the cold from the bottom. Merrell's waterproof membrane helps seal pour the water and snow, and the waterproof leather and mesh upper ensure our feet stay dry while still being able to breathe. The zip-up design uses a premium YKK waterproof zipper to ensure no water gets in our boot, and a molded rubber toe cap protects the front of the boot from freezing when the leather is wet in sub-freezing conditions. Merrell's Air Cushion in the heel of the boot helps to absorb shock and reduce fatigue, and the Super Rebound Compound midsole helps to keep us moving over rough terrain.