These down foot warmers use high-quality down with excellent heat retention and can be stored compactly. The drawcord adjusts the fit around the ankles, preventing them from slipping off during sleep or walking. The lining uses a non-slip brushed mesh fabric. The stretchy material at the opening prevents cold air from entering. These are suitable for cold protection in mountain huts, tents, during rest, or while sleeping. Specifications 【Material】Outer fabric: 10-denier Ballistic® Airlight nylon [water repellent treatment] Lining: CLIMAPLUS® Mesh [polyester] Insulation: 650 fill power down 【Average weight】142g 【Sizes】S (22-24cm), M (24-26cm), L (26-28cm) Thank you for viewing. Purchased in 2020 and used a few times. Please check the images and only purchase if you understand that these are used items.