Borosilicate Glass We have chosen to create our Verona range from high-quality borosilicate glass, as this will offer a strong construction whilst ensuring the cup will not be affected by high or low temperatures. It is possible to pour hot water into the ice-cold mug. Each set comes boxed in our carefully designed presentation boxes making these an ideal gift for housewarmings or any special occasion. Please note no matter how strong glass we use, all glass and can be broken, so we recommend always being careful when using and hand washing which will lead to a longer lifespan.