Brand new, unused item! Size M [Comfortable Down Shoes] These down socks use high-quality 90% goose down, making them fluffy. The insulation rating is 700FP. The fabric and lining are made of 20D 400T nylon cloth with precise stitching, which is waterproof, skin-friendly, durable, and not easily damaged. Applicable temperature: 0°C to -15°C. These are recommended as winter cold protection! [Compact and Lightweight] S: Expanded size: 26 x 12 x 23 cm, Storage size: 13 x 9 cm, Weight: approx. 80g (including storage bag). M: Expanded size: 29 x 15 x 23 cm, Storage size: 14 x 9 cm, Weight: approx. 90g (including storage bag). The size after storage is approximately 9cm * 14cm. The cold-weather socks are compact and lightweight after storage, making them easy to put in a backpack or suitcase, and they don't take up much space.