Vial Vial part number Septa Material Cap/Septa part number; 220-91521-10: Clear - Low Volume-PTFE/Silicone, ultra-clean-220-97331-23: Clear with write on spot: 220-97331-17: PTFE/Silicone, ultra-clean: 220-97331-20: 220-97331-23: Amber with write on spot: 220-97331-18: PTFE/Silicone, ultra-clean: 220-97331-20: 220-97331-24: Amber with write on spot: 220-97331-18