Bel-Art Spinwedge Teflon Magnetic Stirring Bar; 12.7 x 50.8mm, White (F37123-0003) Triangular wedge shape disperses sediment on the bottom of a container, stirs viscous liquids and solutions, and provides turbulence at slow speeds Teflon (PTFE) casing is chemically inert, can be used with corrosive chemicals, and helps reduce friction and wear while spinning Smooth surface allows the bar to spin on the bottom of the container to disperse light sediment and air bubbles Internal magnet made from alnico V, an alloy of aluminum, nickel, iron, and cobalt Casing material is approved for use in food, drug, and cosmetic applications