X100 Cap Chromacol screw with septum polypropylenewith PTFE Thermo Scientific 8mm Autosampler Vial Screw Thread Black PP Caps, blue PTFE/white silicone preslit septaClosure Color: Black, Closure Material: Polypropylene, For Use With: 8-425 Standard-Opening Vials, PTFE, Silicone, Screw Cap