The lid has a silicone rim for air-tight seal, keep food fresh longer and protect against air moisture. Great for wet sauces, jams , cut fruits or dry foods like beans , rice , pasta , baking goods like flour , powders ,salts , sugars , cookies, cereals, tea leaves and spices or other ingredients. With the wide mouth, can easily wash your hands or cleaning utensils, dishwasher safe, save your time. Each jar cover comes with a food grade silicone sealant ring ,more effective in preventing fluid flow and the entry of gases and bugs, better food preservation.