Silicone / PTFE (Polytetrafluoroethylene) septa, kuma aka sani da silicone // PTFE liners ko iyakoki, ana amfani da su a dakunan gwaje-gwaje da sunadarai na nazari don rufe samfurin vials ko kwantena. Wadannan septa suna ba da hatimi mai aminci da abin dogara don hana samfurin ƙafe ko gurɓatawa.Silicone \/ PTFE septa ana amfani da su sosai a aikace-aikace irin su gas chromatography (GC), chromatography na ruwa (LC), nazarin sararin samaniya, da samfurin ajiya. Ana samun su cikin girma dabam da jeri daban-daban don dacewa da takamaiman vial ko nau'ikan kwantena, suna tabbatar da amintaccen hatimi mai dogaro don hanyoyin gwaje-gwaje daban-daban.