2mL 9mm Screw Thread Vials with PP Caps and Red PTFE/White Silicone Septa. Aijiren Tech 2mL 9mm Screw Thread Vials are constructed from from Type 1 borosilicate glass, with low metal content, to protect your sample from destabilizing or leaching..9mm Vial is screw thread vials with a 9-425 GPI thread and the closure is dimensionally equivalent