- The primary materials that compose this product contain a minimum of 20 percent recycled content. - Smartwool® Run Zero Cushion No Show Socks have a no-show silhouette designed to stay hidden in active footwear. Featuring a sewn-in binder and internal heel gripper for a secure, stay-in-place fit. Indestructawool™ durability technology is intentionally knit into high-impact wear zones, helping your socks outlast your longest adventures. 4-Degree™ Elite Fit System offers a performance fit with strategic stretch and mesh zones to promote breathability while helping protect against blisters. Virtually Seamless™ toe technology is a flat knit toe seam designed for additional comfort. - Athletic socks. - Pull-on style. - 51% Merino wool, 46% recycled nylon, 3% elastane. - Machine washable. - Made in the USA.