our glass tubes for glass blowing are fashioned from borosilicate glass; Known for its unbreakable nature and resistance to high temperatures, borosilicate glass is the perfect material for these purposes; The clear color of the tubing enhances visibility and adds an aesthetically pleasing touch; Its strength and compatibility with microwave ovens and dishwashers make these glass tubes a truly utility product each borosilicate glass tube measures approximately 4 inches/ 10 cm in length, 0.47 inch/ 12 mm OD, 0.31 inch/ 8 mm ID and 0.08 inch/ 2 mm in thickness, which is the perfect size for various institutional and personal needs; The package comes with 12 glass tubes of the mentioned dimension along with 2 cleaning brush, thus ensuring you are well equipped for your tasks these are not just ordinary glass blowing tubes; These borosilicate glass tubes also serve as perfect glass test tubes suitable for laboratories, schools, and factories; In addition to professional use, do not limit your creativity as they can also be applied as drinking straws or for various DIY projects our glass tubing sports a smooth surface and thick glass that is resilient to high temperatures; This makes them safe to be applied in microwaves and dishwashers; Moreover, both the ends are fire polished ensuring no harm to your hands, amplifying safety and longevity our industrial glass tubing is characterized by its high level of transparency, which makes it an perfect choice for laboratory work where observation and precision are paramount; Furthermore, this elements of our product allows it to be functionally effective and visually appealing simultaneously Colour:As Shown Material:Glass Package Contents: 2 set x glass blowing