This set contains six 12-ounce glasses, made by the original French tumbler company. The Picardie tempered glasses are suitable for hot or cold drinks and can be stacked conveniently. Duralex glass is 2-1/2 times more resistant to breakage and chipping than normal glass and can withstand sudden thermal shock from -4-degree F to 212-degree F. It is also very hygienic, being non-porous and does not absorb liquids, colors, or flavors. The products are dishwasher, fridge, and microwave safe and will maintain their original look for years.