The LIVIVO Set of 2 X 280ML Double Wall Coffee Mugs keep hot drinks hot without burning fingers and cold drinks cold without messy condensation, making them the ideal vessels for every beverage, from a smooth cocktail to rich cocoa or mocha-chino. Made from mouth-blown beautiful borosilicate glass, which is light and robust at the same time, with an intelligent silicone vent located at the bottom of each glass that equalizes the air pressure between the glass walls.