These Mid Weight Mid Length Waterproof socks from SealSkinz are a calf length medium weight sock with a Merino Wool loop pile lining for warmth and excellent wicking performance. These socks are suitable for a wide range of outdoor activities. All SealSkinz socks incorporate unique seamless, close fitting, three-layer technology which reduces friction between the foot and shoe, providing in-built blister reduction. The close fitting inner actively wicks sweat and moisture away from the skin. The waterproof, highly breathable membrane ensures feet are always comfortable and dry.These socks now also have an elasticated instep and Achilles for additional support and a better fit. All SealSkinz Socks, Gloves and Hats have an individual Thermal Rating, ONE being for mild weather conditions and FIVE for extreme cold weather conditions.These Socks are rated THREE.(11/11)