ND20 crimp headspace gc vial. According to different materials, it can be divided into two types, one is domestic borosilicate, and the other is imported first-grade hydrolyzed glass to China Gas Chromatography Crimp-top 20ml Glass Headspace . China Gas Chromatography Crimp-top 20ml Glass Headspace Nd20 Vials With Aluminum Gold Caps Ptfe Septa Borosili 3.3 Vials , Find Complete Details about China