Microwavable, dishwasher-safe, and shatter-resistant, the Gigogne tumbler is amazingly durable. It is 4 times stronger than regular glass because it is manufactured through a unique process of extreme heating and rapid cooling. This process leads to a final product that eliminates the need to heat food or drink in plastic and then transfer to glass, saving you time and effort when it comes to dish washing. As with other Duralex products, these are dishwasher and microwave safe, 100% recyclable, shock resistant, and made in France. Sold in sets of 6.