Polygonal stir bar spins freely in a disk-shaped PS capsule to reduce turbulence, center the bar, prevent spin out, protect probes and other instruments in the container, and isolate the bar from chemicals
Stir bar has a chemically inert Teflon (PTFE) casing, which is chemically inert, can be used with corrosive chemicals, and helps reduce friction and wear while spinning
Capsule is made from PS, which resists wear
Spins on the bottom of the container to disperse sediment and air bubbles
Internal magnet made from alnico V, an alloy of aluminum, nickel, iron, and cobalt