Aijiren 2 ml crimp top vials are constructed from Type 1 borosilicate glass, with low metal content, to protect your sample from destabilizing or leaching. The associated crimp caps come with a choice of either PTFE/silicone, PTFE only, natural red rubber, butyl, or PTFE/butyl septum materials. The 2 ml crimp top vials and 11 mm crimp caps are