Durable single wall Borosilicate glass Push button flip action lid Easy fill wide opening Hand wash only Bottle has the ability to withstand extremely hot temperatures without breaking but will be very hot to the touch To prevent burns we do not recommend using for hot liquids Packaged in reinforced protective cartons for no additional charge If the bottles do happen to break Borosolicate glass will not shatter into shards or sharp pieces like traditional glass Instead it will break apart into chunks