The K2 family of Multifrequency Cross-Correlation Phase and Modulation Fluorometers introduces a new approach to fluorescence and phosphorescence instrumentation for the research laboratory. Its optical design and automatic instrument control are state-of-the-art for steady-state and dynamic fluorescence measurements. Its full automation and user friendly software make the instrument easy to use for both the student and the scientist. The K2 operates as a steady-state fluorometer for the measurement and analysis of excitation, emission, and polarization (anisotropy) spectra; for synchronous luminescence spectra; and for kinetics studies. The K2 is a multifrequency cross-correlation phase and modulation fluorometer for decay times determinations with picosecond resolution; for the measurement of rotational correlation times of molecules; phase and modulation resolved spectra; and for phase and modulation resolved kinetics lifetime.