Thin Septa Vials. I-Chem. Clear borosilicate glass with 0.060 in. Thin Septa 40 mL clear septa vials feature a thin (0.060”) PTFE/silicone septa. The septum is easy to puncture with syringe needles and is ultrasonically bonded to the 24-414 polypropylene closure. No adhesive is used.