20mm Crimp Top Aluminum Caps with Septa. Suitable: 20mm Crimp Top Headspace Vials. Caps Material: Magnetic Aluminum. Septa Material: PTFE/Silicone; PTFE/butyl. Septa Size: 20*3mm. Cap Features: 8/9.5mm Centre Hole. Color: Metal Silver. Send Inquiry Chat Now. TAGS: 20mm-crimp-vial headspace-crimp-vials vial-cap aluminum-cap crimp-cap crimp-vial.