Spinfin® magnetic stirring bars agitate liquids in round bottom vessels such as test tubes, cylinders and flasks, where other stirring bars cannot be used.Maintains its position in a vessel and will not wobbleAlnico magnet encapsulated in FDA Grade, USP Class VI Teflon® brand PTFE Coating – Superior Chemical CompatibilityManufactured in a registered ISO 9001:2015 facility, as verified by SGS certificationAutoclave safeTEFLON® is a registered trademark of The Chemours Company FC LLC and used under license by Bel-Art Products, Inc.