Food grade silicone, BPA free, Non-toxic,durable, soft texture,sustain the temperature form -30 up to 230℃, no worries for the silicone stretch lids be damaged. The silicone storage covers come in 6 sizes so there’s always one that fits. Silicone tops are round yet stretchy enough to fit snugly over odd-shaped mugs, pots, bowls, and containers. Leak proof with an air-tight seal so foods stay fresh and tasty. Silicone stretch lid replaces plastic bag, reused after cleaning, safer, environmental protection and healthy. Keep food fresh. Perfect fresh food cover for barbecue outdoors or travel with your friends, and the fresh food cover doesn’t spill food and water in your car.