Pioneering the use of a unique hydrophilic membrane, this 100% waterproof yet breathable sock pulls moisture away from your skin at a molecular level for exceptional comfort. Featuring a three-layer construction for warmth, durability, and waterproofing, it has a merino wool lining for superior moisture control, insulation, and comfort. Flat toe seams prevent rubbing, and the Hydrostop feature, a silicone-free elastic taping inside the cuff, reduces water dripping down your leg. Zonal elastication provides added support. Please note that due to the close bond between the sock cuff and skin, prolonged use may cause minor skin irritation for some users. For those experiencing irritation, it is recommended to use Hydrostop socks outdoors only and not for extended periods.