A flexible stereo microscope for advanced research work in biomedicine and industrial quality control. The Greenough optical system delivers impressive 3-D images in a zoom of 6.7:1, giving a magnification range of 7.5X-50X in the standard setup. The implemented click-stops allow precise reproduction of magnification for measurements through eyepiece reticles. The instrument comes without illumination: Choose the best external illumination that meets the requirements of your samples.