Duralex - Wave Clear Stackable Tumbler 12 Ounce Set of 4 Set Includes: Four Clear Tumblers 12 oz. Duralex is 2-1/2 times more resistant to breakage and chipping than normal glass, can withstand sudden thermal shock. Can also withstand sudden thermal shock, from -4f to 212f Dishwasher, refrigerator and microwave safe, Products maintain the original look for years Duralex glass is very hygienic, It is non-porous and does not absorb liquids, colors or flavors