lab vials supplier 2 mL crimp top vials are constructed from Type 1 borosilie glass,with low metal content,to protect your sample from destabilizing or leaching. Our associated crimp caps and closures come with a choice of etiher PTFE silicone,PTFE only,natural red rubber,butyl,or PTFE butyl materials. VWR autosampler vials, inserts, and closures