Yosemite mid-calf heavy weight boot sock has thermalined construction that provides warmth for cold weather adventures or regular winter wear. The Merion wool softness and wick dry technology profide great comfort. Contoured rib top holds socks in place to eliminate slippage. The reinforced heel adds durability and longer sock life. Made to resist the friction that causes blisters and hot spots and have a smooth, flat comfort toe seam.