Broad range of EPA Vials in clear and amber glass. Virtuoso glass vial, 2 ml, ND 9, clear, screw cap w. PTFE/silicone . Made of high-quality 33 Expansion Borosilicate clear glass, Type 1, Class A. These vials have a uniformly flat bottom PTFE/silicone septum, 100 pc/PAK. CeiExpert. 9mm screw thread caps, septa, and vials are Clear vial, 33