Heavy walled PTFE Starburst/Cross Stir Bars have a larger vortex and provide excellent mixing at slow speed. Starburst Stir Bars are a very stable, general purpose stirrer. Stirrer magnets are made from FDA approved PTFE. They feature Alinco V magnet cores and Isostatic encapsulation to eliminate cracks and porosity. PTFE Stir Bars have a polished finish to reduce pick-up and cross contamination. They can be sterilized using thermal or chemical means.