Jars are ideal for storing and collecting specimens and lab supplies. Wide neck and straight sides facilitate easy recovery of contents. Rigid Clear Polystyrene Jars offer glass-like clarity with a smooth surface that is slip-resistant. Natural Polypropylene Jars are translucent and durable. Polypropylene offers greater tolerance to high temperatures than HDPE and better contact clarity. Co-polymer Jars are made from polypropylene and styrene. This combination gives the jars great temperature tolerance and rigidity. White Polypropylene Jars are ideal for solids, powders and cosmetics.