Headspace crimp top vial, 10 mL, 23 x 46 mm, clear, round bottom. Maximum recommended fill volume is ½ full: Cap: (100/pk) Headspace crimp cap with septa, 20 mm, silver aluminum cap, PTFE/silicone septa. For any headspace applications using a pressure over 45 PSI, use of a safety release cap is strongly recommended to prevent damage