Norrona Senja Merino Lightweight Long Socks 7718 40-42. These socks are designed for trail running by creating quick dry and low friction functionality but can be used for all kinds of outdoor activities. They are using a combination of 40percent Merino wool 56percent polyamide and 4percent elastane because they believe this creates the best socks for trail running. The wool because of its temperature regulation natural order-resistant properties and its ability to absorb moisture in a good way. The polyamide for its strength quick dry and is low friction. The elastane for the ability to create stretch but they want to use as little as possible because of elastanes moisture absorption. The 215 micron merino wool is GOTS certified. Key features include: Extra cushioning at the bottom of your feet for increased protection. The arch of the product has been outfitted with a snug premium Merino Wool band that will keep them in place. And both the heel and the toe of the socks have been reinforced for maximum defense against typical sock holes. The fit is technical. Specifications for Norrona Senja Merino Lightweight Long Socks: Manufacturer: Norrona Gender: Unisex Age Group: Adults Sock Height: Hight Footwear Type: Socks Activity: Outdoor Fabric/Material: 40percent Merino Wool 56percent Polyamide 4percent Elastane Fire Resistant: No Tactical: No Seasonal/Temperature Use: All Seasons Features of Norrona Senja Merino Lightweight Long Socks Ankle rib knit Cushion french terry knitted sole and heel Knitted logo Left foot/right foot fit Tight knitted arch panel support Package Contents: Norrona Senja Merino Lightweight Long Socks Norrona 5802-23-7718-40-42: Senja Merino Lightweight Long Socks 7718 40-42