Borosilicate glass is a type of glass that is known for its strength and durability. It is also resistant to thermal shock, meaning that it can withstand sudden changes in temperature without breaking. This makes it a good material for water bottles, as it can withstand being filled with hot or cold water without breaking.

Additionally, borosilicate glass is non-porous, which means that it does not absorb odors or flavors, making it a good choice for storing water or other beverages.

It is also easy to clean and does not retain germs or bacteria, making it a hygienic choice for a water bottle.