Thank you for viewing. From the HP: Insoles made entirely of 100% wool. Wool excels at heat retention, keeping your feet comfortable even in the cold winter. The inner and back layers utilize "Kurehalon(R)", a mesh structure known for its breathability and cushioning. This reduces stuffiness and provides a soft feel. Furthermore, the activated carbon sheet in the inner layer effectively eliminates odors, making these luxurious insoles recommended for winter. Thank you for your understanding regarding home storage.