Completely PTFE-laminated, molded Butyl/PTFE septum with a temperature resistance of -40 °C up to 120 °C and a good analytical purity. The bridges of the cap's scorelines break open at an internal vial pressure exceeding 3 bars (± 0.5 bars), thus releasing overpressure in a crontrolled way. Functionality of the cap is not depending on the design of the vial's crimp neck (beveled top, flat crimp neck).