N 20 Aluminium pressure release safety cap, silver, center hole Butyl light gray/PTFE dark gray Hardness: 50° shore A Thickness: 3 mm pack of 100

Butyl/PTFE closures with a good analytical purity. Equivalent closure to 70234.8, however, with a punched septa instead of a molded one. Very good price performance ratio. 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).