Integrating spheres are available that connect to Ocean Insight spectrometers and optical fibers to measure the spectral output of LEDs, lasers and other light sources. Each sphere consists of diffusing material that provides a Lambertian surface for irradiance measurements. Various sample port sizes are available and some models can be attached directly to the spectrometer. This integrating sphere attaches directly to USB2000+/USB4000 spectrometers.