These Cooking and Storage Lids create an airtight seal to cook and reheat without messy microwaves and stovetops and storing leftovers. They're reusable and more airtight and economical than plastic food bags, cling wrap, or aluminum foil. This set includes (1 each) 9, 10.5, and 12-inch silicone lids to quickly cover and seal most pots and pans, mixing bowls, microwaveable bowls, and food storage containers, contain splatters, and lock in heat and steam for faster cook times in the microwave or on the stove. No more digging for the right-sized lid. They seal plastic, glass, ceramic, metal, and other materials with a smooth, unfluted edge.