These tubes are made of high-quality Borosilicate 3.3 Glass and have Bakelite screw caps with rubber liners, ensuring a secure, leak-proof seal. They are ideal for various laboratory applications such as chemical transfer, sample storage, and biological handling and culturing. These autoclavable culture tubes are highly durable chemically and can withstand high temperatures and thermal shocks while exhibiting a low temperature gradient. Each tube measures 0.7" wide and 5.9" tall (including cap). They are versatile and perform well for needs in the food and beverage industry. Additionally, they are suitable for crafting and storage in home or garage settings.