Enhanced with cutting-edge warmth, our Mens Trans-Alaska Pac Boots now have SolarCore aerogel barriers underfoot and in the toes. Tested and verified by an independent research laboratory, this NASA-inspired SolarCore insulation technology retained 54% more heat over a 30-minute period at 10F than traditional insulation. Additional warmth is supplied by 13mm Texel removable liners that reflect heat inward to minimize heat loss, moisture-trap footbeds that wick away perspiration and condensation, 1/2 layers of EVA foam and nylon-covered Phylon midsoles that put 3 of cold-blocking material between your feet and the ground. Tough, flexible vamps are protected by triple-layer, abrasion-resistant toe guards and rubber toecaps to ensure longer wear. Lightweight waterproof shells and reflective nylon shafts. Waterproof, breathable 4MOST DRY-PLUS linings keep feet dry. Radiantex reflective coating. The 8 liners allow for pants inside the boots, and the nylon-ripstop gaiters have a cord-locked drawcord to keep out snow. These boots are easy to tighten, thanks to a one-pull ball-bearing lacing system. Inside, a heat-pack pocket allows you to insert toewarmer heat packs. Order next size up if wearing with heavy socks. Ht: 15. Avg. wt: 5.8 lbs./pair. Mens whole sizes: 7-13. Color: Black/Red. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Boots.