This Jingdezhen Heat Resistant Glass Tea Set is made from high borosilicate glass material which has been recognized as an international patent. Therefore, it is lighter but much stronger than common glassware. The corrosion resistance capacity of borosilicate glass is qualified to be used for making laboratory glassware. Even after a long time of use, it will still be shining brightly as if it is brand new. It can stand a temperature gradient scale between -20 to 150?? safe for containing boiled water after 12 hours stored in the freezer and thus applicable all year round. This Glass Tea Set is all hand made and every item is unique in the world. The hand-made craftsmanship ensures a smooth, natural and delicate exterior that can never be paralleled by machine moulded products. It is definitely safe and convenient to use in modern life.