This process of roto molding allows for a complete product that does not have inserts. There is no assembly of the plastic parts This is necessary for good insulation. The wall thickness is uniform and the corners are stronger and thicker, where it’s needed.The lid has a complete fridge type gasket seal that ensures that the cold on the inside is kept as long as possible. Ice can hold over a week.The polyurethane insulation that is used is ‘green’ and is ozone friendly. It does not omit harmful CFC’s into the environment. The insulation assists with keeping the contents of the cooler box cold. Both the box and the lid is insulated with the foam.