20mm Crimp Top Caps provided by STE-Mart are made of aluminum for crimping and sealing. Crimp Caps squeeze the septum between the rim of the glass vial and the crimped aluminum cap. This forms an excellent seal preventing evaporation. The design with a 9.5mm hole in the center of the cover can be used for headspace analysis.
Specification
Caps Material: Magnetic Aluminum Cap Features: 8/9.5mm Centre Hole Color: Metal Silver