The Reusable Flexible Lid creates a vacuum seal that allows you to preserve food in the refrigerator easily and hygienically, preventing contamination and prolonging freshness. This lid is especially useful with leftovers in either metal, plastic or glass. It is even suitable for preserving fruit and vegetable halves. A vacuum seal is achieved by simply pressing down on the top. Due to the product's elasticity it easily adjusts to containers of all shapes and sizes.