This product has good heat insulation, and the constant temperature effect is very great. So it is used to keep cold, heat preservation and preservation. It is made of high quality materials and is easy to carry. Therefore, we use it when we're on a car trip, on holiday or on a picnic. The inner layer of the product is sports pearl cotton and then composite with aluminum foil into a reflective and heat insulation layer, so aluminum foil insulation bags have a fantastic effect of heat preservation.