Instruments in the Zetasizer range are used to measure particle and molecular size from less than a nanometer to several microns using dynamic light scattering; zeta potential and electrophoretic mobility using electrophoretic light scattering; and molecular weight using static light scattering. The Zetasizer system is available in a range of variants, including the new Zetasizer Pro and Ultra. These two new systems offer unprecedented ease-of-use and flexibility, along with empowering user guidance and novel measurement techniques such as MADLS® and Particle Concentration.