Features: 1.These handy covers are made from super-stretchy silicone. 2.They are circular in shape but pliable enough to seal even odd-shaped containers. 3.The tops are made from bpa-free, food-grade plastic. 4.They are microwave and dishwasher-safe. 5.They are also heat-resistant to 450 f, so reheating foods is never a problem. 6.Save on expensive, disposable plastic wrap, and save money on food bills by storing scrumptious leftovers for another meal.Flexible Size: 7.1cm (will stretch to 8.9cm ) 9.4cm (will stretch to 13cm ) 11cm (will stretch to 15cm ) 14cm (will stretch to 20cm ) 17cm (will stretch to 23cm ) 21cm (will stretch to 28cm )How to use it. meal.Flece half of the lids over one edge of the meal.Flert on the side closet to your body. meal.Fleetch the other half of the lid away from you,inching your way around the bowl. meal.Fleetch,then press the top of the lid while pulling the tabs to create a vacuum seal. meal.Flel the sides to ensure a perfect meal.Fleice: Sturdy stretch lids is made of high quality silicone, can be used for a long time.Heat resistance from 40 ?(freezing) up to 400 ?.Safe for Oven or meal.Fleming tips: meal.Fles are completely dry or they will not stay in place. meal.Flen you are using it in Microwave or Oven,do not completely seal container would be better.Because the expanding heat and pressure from container, may result in damage or injury.