(Quick cooling in the freezer for about 40 minutes in 30 minutes) The cooling mechanism of this product cools down by freezing about 60% of the moisture contained in the 0.1 inch (3 mm) desiccant to cool down in an indirect ice cold. Therefore, unlike direct ice cubes, it is characterized by natural cold air. Also, the 3mm crush freeze in the freezer. (It takes about 3 hours of icinon) It can be quickly cooled, so you can quickly cool down your muscles after your body is moved. In addition, the desiccant absorbs sweat in the affected area to keep you dry and comfortable. The gel type will quickly warm up in 20 minutes, but it is very convenient to maintain a long cooling duration of about 40 minutes. In particular, if you put it on your forehead with the wisdom of your child, it cools against the skin, and is gentle on the skin, so you dont have to worry about cold burns. It is very useful when you need stiff shoulders, sore muscles, or hot weather. How to Use: Place in the included zipper bag and let it cool in the freezer for about 30 minutes or more before using. Please use the affected area for approximately 20 minutes. If the cold becomes weak, please give us a better cooling power. Effect: Indirect cold air from desiccant agent; Sweat absorption; Deodorization; Shelf life: Approximately 6 months (sweat and other proteins are also absorbed and clogged, so you can change them quickly.)