A typical jar of preservation resembles a tall vase or flat-bottomed amphora in shape. They are designed to be easy to tip over, as this is the preferred means of extracting food items from them. They are usually 2-3 feet tall and slender in form. Each one has a pair of carrying handles near its neck; when transported by hovership, ropes are run through these handles to tie them together.
Jars of preservation are usually sold together with their contents as a unit. Empty jars of preservation are then sold back to the merchant for a deposit. People will often keep personal jars of preservation to save leftovers or keep smaller portions of food. However, it is rare for people to purchase a jar of preservation as a stand-alone appliance, as one would a terrestrial refrigerator; it is much easier to simply buy food and not return the container.
The principle behind the jar of preservation is very similar to the principle behind the preservation amulet.