This lunch bag is made of 3 layer material, the outside layer is thick oxford fabric, the middle layer is 6mm thick Insulation EPE foam, the inside layer is thick aluminum foil. The thickened lunch bag could keep food cool or warm for more than 5 hours. The lunch bag size is 9.8 inch length, 6.7 inch height, 5.9 inch wide. The PEVA lining is waterproof and easy to clean stain. The thickened material lunch bag could reusable use for years and the zipper is heavy duty metal.