Durable glasses made in France since 1939. Duralex tempered glass is 2.5 times stronger than ordinary glass. Manufactured to withstand sudden temperature extremes from -4 Degree to 266 Degree and is suitable for hot or cold liquids. Adaptable modern glassware can go directly from the freezer to the microwave. Duralex glasses and bowls are stackable for convenient and space saving storage. Nonporous Duralex glass does not absorb liquid. Constant quality control guarantees excellence and built in durability insures that Duralex products will maintain their look for many years.