GORE-TEX These insulated pants are for coldest days in the backcountry when weather protection is a must. The shell pants, engineered with GORE-TEX Performance Shell uses the most durable nylon face fabrics available. The 2-layer construction uses a GORE-TEX membrane. which is bonded to the outer material and protected on the inside by a separate lining for better wear, greater comfort, and waterproof/breathable protection. And the shell pant is packed wtih 60-g Thermogreen insulation for reliable core-warmth protection.