A sealed ampoule of pressurized liquid Dinitrogen Tetroxide. The exact composition is N2O4. This amazing sample is in liquid form which is not commonly seen. This fits perfectly inside the included 1 dram vial for display. This would make a great sample for teaching purposes or for the collector of unique and strange science stuff. Please check my Bonanza store for more element samples. I have almost every collectible element available. Thanks for looking.