Duralex Made In France Orleans 12 3/4 Oz Clear Mug, Set of 4 Set includes four 12 3/4 ounce mugs 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 -4f to 212f 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