High quality, FDA food grade approved, BPA free and Freezer safe silicone lids, which will create a perfect seal on pyrex, anchor, corningware, corelle, or any other plastic or metal containers for secure fit, helping to keep food fresher and for longer. Extra thick silicone is durable and will not tear or warp. They can be used over and over again, and are microwave, dishwasher, oven safe and freezer safe. They will remain intact even in freeze or heat within the temperature rated -40F/-40C