Screw 8-425 (8mm, N8) HPLC Vial, Cap, Septa an Application: Suitable for 8-425, 9mm, 10-425, 11mm snap vials Material 2 mL Screw Top Vials and Caps | Aijiren The associated 9 mm screw caps and closures come with your choice of septa constructed from either PTFE silicone or natural red rubber.