Duralex Made In France Lys 4-Ounce Clear Round Bowl, Set of 6 Set includes six 4-ounce bowl The original french tumbler, made by the company that invented tempered glass Duralex is 2.5 times more resistant to breakage and chipping than normal glass, can also withstand sudden thermal shock from-4-degree f to 212-degree Dualex glass is very hygienic: It is non-porous and does not absorb liquids, colors or flavors Dishwasher, refrigerator and microwave safe; products maintain the original look for years