Made in 100% silicone material. It has good flexibility. It can seal any container sharp up to 9inches with dishwasher, mircoware and freezer safe. Max resisitant temperature: 250 degree Min resistant temperature: -40 degress. Flexi-fit lids create an airtight seal that locks flavor and freshness. Silicone covers \"stretch\" to fit round, square or oddly-shaped containers you will never waste time searching for a matching lid again. Freezer, microwave and dishwasher-safe pair come in two sizes: 3\" and 7\" diameter. Use them on almost any container, anywhere in your house. It\'s supposed to fit any shape container--round, oval, square, even rectangle. Never throw out leftovers again! Currency: USD Unit Price: Quantity: Delivery: