Double Wall Thermal Espresso Glasses, Made of tasteless-borosilicate glass that are light and robust at the same time. The mouth-blown double wall design keeps your coffee hot longer, while protecting your fingers from the heat. Under the glass floor is a hydrophobic silicone membrane, which serves to equalize the pressure between the glass walls. Apart from being used for coffee and espresso, these cups are also a creative way to serve your guests ice cream and dessert! 12 Oz (The actual capacity may be short of 12 Oz when using. 1. Important: Hand wash recommended, Please avoid contacting with sharp objects when cleaning. 2. There may be slight differences between the individual items because Each hand-blown and hand-crafted.