Spinring® stirring bars provide maximum stabilization of the magnetic stirring bar with the addition of a removable "hoop" around a standard octagonal bar.Best suited for larger open-neck vessels, such as buckets and beakersFriction fit of the hoop and bar allows them to spin as a unit, virtually eliminating "spin out" while keeping the bar centeredOctagon shape creates a deep vortex without splashing or chatteringAlnico magnet encapsulated in FDA Grade, USP Class VI Teflon® brand PTFE Coating for superior chemical compatibilityManufactured in a registered ISO 9001:2015 facility, as verified by SGS certification; autoclave safeNote: TEFLON® is a registered trademark of The Chemours Company FC LLC and used under license by Bel-Art Products, Inc.