Starfrit Gourmet Swirl collection offers double wall glasses made of borosilicate glass. The double wall concept creates an isolation barrier. Keeps the temperature of what is in the glass constant much longer than standard glasses. Also great for appetizers and desserts. No more rings on tables, there is no condensation on the glass. Dishwasher, freezer and microwave safe. Coffee mug 360 ml/12-Ounce