It uses high-spec down material with 800 fill power that can be used in extremely cold fields, and the outer material is made of breathable and waterproof material, so you can stay comfortable in all kinds of weather, including rain and snow. By using water-repellent down, we have overcome the problem of down's inherent ability to retain heat when it gets wet, and made it possible to wash it at home. The outer material is tear resistant and has excellent stretch properties, making it comfortable to wear.