Screw Caps with Septa for 8-425 Screw Neck Vial. Suitable for: 8-425 Screw Vials. Caps Material: polypropylene. Septa Material: PTFE / Silicone. Septa Size: 8*1.5mm. Cap Features: 5.5mm Centre Hole or Closed Top. Color: Black, White or Customized. Send Inquiry Chat Now. TAGS: