Bodum's insulated glassware is made from durable Borosilicate glass. Borosilicate glass is a strong, heat resistant glass that weighs less than traditional glassware. Used to make scientific lab glass, the boron oxide acts as a glue holding the silicate together and due to the small size of boron particles, the glass is held together tighter, resulting in a stronger glass. Dishwasher safe, this glass will look new after years of use.