For a chilly outlook, this Thermo is a climate controller. Merrell used a waterproof leather and nylon upper to stay dry docked, while stuffing 200 grams of Primaloft insulation to buffer against the cold. Q-Form EVA footframe is designed for women in wind, and ensures anatomically correct stride alignment. Deep lugs on the Thermo Women’s sole tread solid on any tundra. Waterproof Construction. Waterproof Nubuck Leather and Nylon Upper. Polartec 200 Thermo Insulation Lining Treated with Aegis Antimicrobial. 200 grams of Primaloft Insulation. 4.5mm Anatomical Footbed. TPU Backstay with Snowshoe Strap Ridge. Nylon 6.6 Injection Molded Arch Shank. Q-Form Triple Density Compression Molded EVA Footframe. Grade 1 Tapered Nylon Insole Molded to Bottom. Merrell Air Cushion Midsole. 6.5mm Sole Lug Depth. Vibram Thermo Womens Sole/Trek Dura Rubber. Comfort Range to -25F/-32C.