Cooling function Peltier vest, capable of cooling up to -23°C and usable for 8 hours. By cooling the base of the neck and underarm areas, it lowers blood flow temperature. It can be used alone, or in combination with a fan-equipped vest for even greater effect. It can also be used in heating mode during the winter. - Model Name: JW-699 - Cooling Temperature: -23°C - Usage Time: 8 hours (when using the fluctuation mode) Unused, only opened for the purpose of taking photos of the contents. Thank you for viewing.