A U-shaped glass tube is a fundamental teaching tool in chemistry experiment teaching, consisting of a glass tube bent into a U-shape with open ends. The tube body is transparent and has a scale, and some parts are equipped with rubber plugs or conduit interfaces. In chemistry class, it can be used as a simple gas generator or gas washing device, such as introducing gas on one side and observing the bubble rate on the other side to determine the reaction intensity. Suitable for middle school physics and chemistry experimental teaching, cultivating experimental observation and analysis abilities, it is the core tool for physics and chemistry basic experiments.