The laboratory container known as a specimen jar, also called a gas jar or PS (polystyrene), is used to store, transport, and examine solid or liquid specimens. It is made of polystyrene, a plastic material valued for its affordability, clarity, and toughness. The container is cylindrical in shape and features transparent walls that allow see into the contents, which are sealed by a tight-fitting cover. Gas jars are frequently used in lab settings for a variety of purposes, such as specimen storage and transportation, live insect examination, or researching the behavior of gases in a closed environment. They are offered in a range of sizes, from little jars for little experiments to big jars for big operations.