These zoom stereo microscopes on single-arm boom stand provides crystal clear sharp clear images. The base model comes with a 7X-45X binocular head with 10X super widefield eyepieces and a sturdy single-arm boom stand. The zoom magnification power can be extended from 3.5X to 225X depending on the choice of the optional eyepieces and Barlow lenses. The 45 degree inclined binocular oculars and high-eyepoint optical design ensures a comfortable observation for all users including eyeglass wearers. The single-arm boom stand allows you to turn the microscope head around two different axes, http://www.amscope.com/