From SmartWool, these ankle socks feature: Comfortable and durable Indestructawool™ technology to the Achilles heel tab to reduce slippage Purpose-driven features that help you get the work done Virtually Seamless™ toe Breathable mesh zones One size fits most men's shoe sizes 9-13 Merino wool/nylon/recycled nylon/elastane Machine wash/tumble dry Made in the USA.