Duralex Lys Stackable Glass Bowls are functional and highly durable yet stylish glass bowls. Duralex glassware is 2-1/2 times more resistant to breakage and chipping than normal glass, and can withstand thermal shock from -4 to 212-degrees F. Duralex has been manufacturing tempered glassware and tabletop products for over 80 years in La Chapelle-Saint-Mesmin in the very heart of France. Microwave, refrigerator and dishwasher safe. Made in France. Set of 6.