... :13*100mm 15*150mm 20*200mm. 4:Scope of application:for scientific research, teaching, medicine, and petroleum chemical industries5: We can ... tube apply to schools as "salt Bridge" chemistry experiment, or for organic semi-trace "quantitative" analysis, a small amount of gas ... , automatic Buret in the apparatus of the gas imported, used for drying moisture-proof. Drying Tube U-shape with two side tubes