Borosilicate glass is a type of glass that contains boron trioxide which allows for a very low coefficient of thermal expansion. This means it will not crack under extreme temperature changes like regular glass. Its durability has made it the glass of choice for high-end restaurants, laboratories and wineries. Borosilicate glass is made up of about 15% boron trioxide, which is that magical ingredient that completely changes the behavior of glass and makes it thermal shock resistant. This allows the glass to resist extreme changes in temperature and is measured by the “Coefficient of Thermal Expansion,” the rate at which the glass expands when it is exposed to heat. Thanks to this, borosilicate glass has the ability to go straight from a freezer to an oven rack without cracking. For you, this means you can pour boiling hot water into borosilicate glass if you wanted to say, steep tea or coffee, without worrying about shattering or cracking the glass. Comes with Silicone Protective sleeve and a Bamboo Straw Content source-https://shopkablo.com/blogs/the-reformist/what-is-borosilicate-glass Gift for your Loved ones