SmartWool Saturnsphere Synthetic Made in USA Supportive arch brace - Holds the sock in place while adding additional arch support. Wool-on-Wool Technology - Adds an extra layer of wool in high-density impact zones to reduce shock and abrasion. Medium cushioning - Impact absorption. Smooth toe seam - Flat-looped toe box for a smooth fit with no irritation. 67% Merino Wool, 31% Nylon, 2% Elastane