High quality teflon encapsulated magnetic stirring bars ensure efficient mixing with consistent results. multi-faceted polygon shape with increased surface area creates added turbulence relative to similar sized, smooth cylindrical bars to provide thorough mixing absence of a pivot ring allow the spinbar to stay close to the bottom of the vessel enabling scraping of solids optimal coupling with magnetic spindrive as entire length of stir bar is in close contact alnico magnet encapsulated in fda grade, usp class vi teflon brand ptfe coating; superior chemical compatibility manufactured in a registered iso 9001:2015 facility, as verified by sgs certification autoclave safeteflon is a registered trademark of the chemours company fc llc and used under license by bel-art products, inc.