Contents: 50 ml (5 x 10 ml)Isopentyl Nitrite - CAS 110-46-3Isopropyl Nitrite - CAS 541-42-4This Rush Ultra Strong - Black Label is ultra x ultra strong, means ultra strong². Not for Beginners! It combines two of the strongest formulars in one ultimate formular, that gets released extremely fast and lasts for an extremely long period of time.Additionally, it uses a Power Pack Pellet. This pellet reliably prevents the aroma from being contained by incoming air after first opening. This way, your small Rush Ultra Strong - Black Label stays fresh, clean and ultra strong² even longer.If you are looking for an ultra strong aroma, ideal to be divided over a long period of time with a persistent high quality of the aroma, Rush Ultra Strong - Black Label is the best choice.