Simple glass syringes for a hypodermic needle, filled with a red fluid that can be seen to glow faintly.
Significance
In May 2009, four vials of the true, authentic Formula were brought back from a future that no longer exists; a future that can no longer come to pass, making this handful infinitely precious as perhaps the only way to safely grant Evolved abilities to non-Evolved persons.
Of the original four, one found its way into Richard Cardinal's hands (after Isabelle Ashford was murdered for it) while the other three were given to Tamara Brooks for safekeeping.
Cardinal's vial was used to restore Peter Petrelli in January 2010.
One of Tamara's vials was used on Abigail Beauchamp in April 2010.