These Seperatory Funnels are made of Polypropylene, giving them excellent contact clarity and strength. They are pear shaped, autoclavable, and have a leakproof threaded screw cap. The Polypropylene stopcock, fitted with a self lubricating PTFE plug, is push fitted to the stem of the seperatory funnel. Glassco is a LabwareHouse premium supplier. This product is ideal for laboratories requiring quality products for research and production control.