J.B. Workforce Traditional Boot Sock Wool, Acrylic, Nylon Content- 50% Wool, 25% Acrylic, 25% Nylon Can also be used for rugged work, backpacking, trekking Timeless classic look can be worn in all seasons Impact Support Zones- Reinforced heel and toe ensure these socks will outlast the competition Preshrunk Merino wool- Easy care wool that is machine washable and tumble dry. Merino Wool is the finest quality of easy care wool for exceptional warmth and softness. Wool features inherent qualities such as wrinkle resistance, colorfastness, shape recovery (resiliency), and is very breathable.