23-25 cm This product combines fiber science with the Japanese tradition of "warmth activation" (onkatsu) to maximize comfort and functionality. Its key features are the "extra-thick ankle pile" and "moisture-absorbing, heat-generating fibers" in a double-layered construction. It thoroughly protects the ankles, the body's "cold starting point," and traps heat inside the socks. Furthermore, the polyester x acrylic hybrid material boasts 15% higher heat retention than wool and excellent durability, maintaining its shape even with daily use and providing a comfortable fit. It's truly a new winter standard that allows you to "activate warmth just by wearing it"! 【"Heat-Generating Warmer Effect" Created by Extra-Thick Ankle Pile】 The ankle area, crucial for cold protection, features a concentrated arrangement of thick pile! It wraps around the ankle 360 degrees like an ankle warmer, blocking out the cold air. Furthermore, the extra-thick pile functions as a "heat-trapping circle," locking in warmth within the socks. By gently warming the San Yin Jiao acupressure point, it promotes blood circulation, spreading a natural feeling of warmth from the ankles throughout the body. It's the perfect cold-weather gear for those suffering from cold sensitivity and for sleeping in winter. 【Double Effect of Moisture-Absorbing, Heat-Generating Material x Brushed Lining】 The latest "moisture-absorbing, heat-generating fibers" absorb moisture and convert it into heat! It generates natural heat using sweat and moisture, providing long-lasting warmth. Furthermore, the entire inner surface features a fluffy brushed lining. The fine brushing effectively traps warm air, providing a gentle touch against the skin and comfortable warmth. This gives you the feeling of "warmth from the moment you put on the socks," preventing chills immediately after getting into bed and supporting a good night's sleep. 【High-Quality Finish for Durability and Cleanliness】 Because these socks are worn every day, we've paid meticulous attention to durability. Utilizing the strong abrasion resistance of polyester and the excellent elasticity of acrylic, we prevent shape distortion and wrinkles. Furthermore, special anti-pilling processing minimizes pilling and linting, maintaining a fluffy feel like new even after repeated washing. The toe and heel areas are reinforced with strong stitching for a tear-resistant design. It's the definitive winter warm-weather gear that can be used for a long time and kept clean. 【Indoor/Outdoor Use - Perfect for Winter Gifts】 The simple and high-quality design fits both women and men. It's a versatile leg warmer that can be used as room socks at home, as well as for short outings or as a cold-weather item in the office. It's also perfect as a heartwarming gift for family and friends who suffer from cold sensitivity, and is highly appreciated as a Mother's Day or Christmas gift.