Reusable lids stretch to fit multiple size and shape containers. 1.Made of highly flexible silicone material. 2.Adapts and form fits to oval,aquare,round and rectangular shapes. 3.Vacuum seal traps in freshness. 4.Hot and cold resistant. 5.Dishwasher safe. 6.Microwave safe. 7.Freezer safe. 8.Saves cupboard space.