Duke Standards, Nominal Diameter:  300 µm,  Monosized,  Polystyrene microspheres,  NIST traceable,  dry, Color: White or Colorless, Application: Particle size instrument calibration, Particle Density: 1.05g/cm³, Refractive Index: 1.59 at 589nm (25©C), Shelf Life: Minimum of 24 months
4330A