This magnetic stir bar with symmetrical stirring fins on top and bottom provides superior mixing. It develops a strong mixing vortex even at low stirring speeds. Provides stirring at the bottom sides and top of the container. Works equally well in flat or round-bottom labware. It has excellent resistance to chemicals and temperatures up to 260°C. Materials: Alnico V magnet encapsulated in tetrafluoroethylene (TFE). Diameter: 3/8 inches (10mm). Height: 5/16 inches (8mm). 1/Case. Nalgene® #: DS6600-0010.