Our Fido storage jars have an air-tight bail and seal closures to hermetically seal out air and moisture. From freezer to countertop, use them for dry, fresh or leftover foods. They're also great as gift containers for homemade delicacies. Gasket and metal ring not dishware safe. Gasket and metal ring not microwave safe. Freezer Safe (Min -20 deg C/-4 deg F). Not oven safe. Hand washing recommended without any cleanser for the gasket and the metal ring.