The technology to keep human heads alive in jars was invented by Ron Popeil, who is one of the many people now utilising the technology. The jars have been used in unison with with cloning technology to be able to store historical figures who had died prior to the technology's invention. The liquid inside the jar is, as one would expect, safe to drink and people have been shown to enjoy the flavour. Heads can perfom normal roles in society, including being President of Earth, but most spend time in the Head Museum.
The full extent of the jars' functionality may never be known, however the jars are all capable of sustaining the life of one human's head. The heads are still able to eat and any waste is presumably filtered. The heads are able to survive out of their jars or an undefined period of time. Jars allow the inhabitant to control robotic limbs and bodies, while the jars themselves can contain attachments such as a pen to sign one's name. Jars are usually open at the top, but lids are available.
- Larger, multi-head jars (3ACV16).
- Dome covered version, seen in Futurama comics, which is able to safely float freely through space.
- Al Gore's rocket jar (4ACV08).