Magnetic Stir Bar Retriever, 250mm/150mm/350mm , Steel Core PTFE Chemical Resistant. PTFE Magnetic Stirrer Mixer Stir Bar,White Color. PTFE stir bar retriever (or Stirring Bar Retriever, Magnetic Stir Bar Retriever) is a separate magnet on the end of a long stick (usually coated with PTFE) which can be used to remove magnetic stir bars from a vessel. A widely used laboratory equipment. The perfect tool for retrieving your stir bar from the bottom of the beaker or flask. Magnet permanently embedded in PTFE rod, Ideal for retrieving magnetic stir bars from particularly sensitive or corrosive liquids