Heat retention time: about 3-4 hours (the more calories the food is, the longer the heat retention time is) cold retention time: about 8-10 hours for frozen food or beverage (used together with 3-4 ice pack, the cold retention time can be up to 24 hours) ice pack is fashionable appearance in appearance, bright in color, fashionable in style, easy to clean, foldable and convenient to store. This product also has the function of heat preservation and is also suitable for winter heat preservation. It is a must for life, travel and leisure. Products are exported to Europe and America, all of which are made of environmentally friendly materials. The quality is absolutely OK.