Dissolved oxygen bottle: Dissolved oxygen bottle, also known as water sample bottle or sewage bottle, is used to collect water or other solution samples. The lower part of the bottle stopper is pointed to facilitate the removal of air bubbles. The wide mouth water seal of the bottle can prevent air infiltration to ensure the measurement Accuracy. Borosilicate glass: Borosilicate glass has a very low coefficient of thermal expansion, which is about one third of that of ordinary glass. It is resistant to high temperatures and can withstand sudden changes in temperature of 200 degrees. Thickened glass: The thickened glass is used, which is high temperature resistant and durable. Smooth surface: The surface of the cup is smooth, with no protrusions and beautiful and generous. calibration scale: The surface scale of the product is clear and easy to observe.