These narrow mouth round carboys are made from natural, medical-grade, USP Class VI passed Polypropylene which gives them extra strength and durability. They are perfect for higher temperature applications up to 135°C. The carboys come with leakproof screw type white 83B PP closure with a thermoplastic elastomer (TPE) gasket, for guaranteed performance. They are graduated and autoclavable. These Polypropylene carboys are iconic lab essentials for large-volume liquid storage and dispensing where autoclavability is desired. Their rugged construction makes them compatible with lab reagents including most acids, bases, alcohols, aldehydes, esters, and aliphatic hydrocarbons.