Polypropylene Screw Cap with Septa – Polypropylene screw cap with precision-fit septa provide an evaporation-proof seal. Bi-layer include silicone and PTFE. Silicone septa for multiple injections. PTFE-lined screw cap for organic samples. Screw caps provide an inert, airtight seal and direct puncture-access to samples with a syringe needle.
