Bon Venu silicone stretch lids are food safe and a great way to eliminate nasty and chemical filled plastic wrap from your home. where to use? the silicone stretch lids can Bear temperature from -40°f to 230°f, they are able to cover foods in refrigerator, microwave oven, etc. however, the lids are unable to work well when they have any moisture. tips for use: please wash the lids before the first time using and after each use, you should wash them with soft tool. dry lids seals better than wet. don’t seal the container at all when using in microwave oven. the stretch lids can fit many kinds of container whether round, square, rectangular, etc. But they may not be sealed when you use in the linear products. 6 sizes for you to choose, different size fits your different needs. (1) 2.64″ (can stretches to 3.5″) (2) 3.66″ (can stretches to 5″) (3) 4.33″ (can stretches to 6″) (4) 5.51″ (can stretches to 8″) (5) 6.3″ (can stretches to 9″) (6) 8.07″ (can stretches to 11″) seal and leakproof the lid can keep food fresh cause it’s sealed when you use the right size. it’s very easy to stretch, please try the smaller size to cover your foods and bowls. if the lids keep sliding off, please dry your container and the lid, also try a bigger one to cover. how to use? step 1 find a silicone stretch lid which is smaller than the bowl. step 2 cover the bowl and hold one side, then stretch another side to fit the bowl. step 3 adjust the lid and make sure it’s sealed. step 4 finished. Put your bowl into refrigerator or microwave oven now!