PTFE septa cap for screw vials-Aijiren HPLC Vials. Septa Cap Vial at Thomas Scientific a 0.125” septa Borosilicate glass vials come with a standard 0.125 in. thick, I-CHEM blue, PTFE/silicone septa in an open-top 24-414 polypropylene cap. The I-CHEM molded-in septa retainer ring holds the septa securely in place without bonding to the cap, so