aijiren 2 mL screw top vials are constructed from from Type 1 borosilicate glass, with low metal content, to protect your sample from destabilizing or leaching. The associated 9 mm screw caps and closures come with your choice of septa constructed from either PTFE silicone or natural red rubber. Our screw top vials and screw caps are the perfect fit for HPLC and GC instrument platforms across a wide variety of applications, including pharmaceutical, environmental, energy and fuels, forensics