Caps/Septa for 4mL vials, 100/pack Temperature limit for Silicone/PTFE septa: -60°C up to 200°C Part number Cap Septa Material & Color Septa Thickness Septa Durometer Size 220-97331-19 Black PP, Solid Cap Silicone (Cream)/PTFE (Red) 1.5 mm 55° shore A ND 13 (13mm) 220-97331-20 Black PP, Center hole Silicone (Cream)/PTFE (Red)