Double-walled glasses with a unique design, made of tasteless borosilicate glass that is both light and robust. Under the glass floor is a hydrophobic silicone membrane, which serves to equalize the pressure between the glass walls. This allows the glass to 'breathe': with cold drinks, no condensation forms on the glass surface and the glass does not leave any unsightly water rings. These glasses are also ideal for serving ice cream and other desserts. Notes: 1. Important: Hand washing is recommended, please avoid contact with sharp objects when cleaning. 2. Suitable for freezer compartment. 3. Suitable for microwave (max 2 minutes / 600 watts). 4. There may be slight differences between individual items because each is hand-blown and hand-crafted.