Product Name: Silk and Linen Blend Double-Layer Socks Size: Fits 23-25cm Quality: 1st Layer (Silk Five-Finger Socks): 100% Silk 2nd Layer (Linen Round-Toe Socks): 92% Cotton, 8% Linen Made in: Japan Manufacturer: Sunayama Socks Co., Ltd. Washing Instructions: Machine wash at a maximum temperature of 30°C on a very delicate cycle (use a net) 【Features of Silk】 Cool in summer, warm in winter Silk has a complex, fine structure that traps air between its fibers, allowing you to stay comfortable throughout the year. Gentle on the skin with ingredients similar to skin Made of protein amino acids similar to human skin, it is a skin-friendly fiber.