Material The product is made of food grade silicone material, BPA free, healthy and safe, with toughness, high temperature resistance and long service life. Silicone lid set has 5 different sizes in total, which can meet your different needs in different occasions and can hold almost anything. . Universal lidUniversal lid for beer glasses and other glasses, coffee, drinks, mugs or as can lids - perfect for garden parties, camping, holidays, family celebrations, as insect protection or to keep the coffee mug warm. How It Works The way vacuum lids work is you gently press in the center and the lid creates an airtight, watertight and leakproof seal. You can then use them to store leftovers, groceries, salads, vegetables, pasta, soup, condiments, etc. They are also ideal for cooking, keeping meals warmer longer, food in the fridge or freezer etc. Reusable and economical These eco-friendly silicone lids can be easily cleaned and are therefore reusable, the stretchy silicone lid replaces cling film and aluminum foil, more environmentally friendly. More economy and more comfort. . Good Sealing Anti-Dust The silicone drinking glass lid sticks to the rim of the cup, dustproof and sealed. It can stop liquid spills even when the cup is tilted. To remove the glass cover, you can simply lift it from the side. .