AmScope 3.5x-90x Trinocular Zoom Microscope + 3D Boom Stand 3.5X-90X continuous stereo zoom magnification power Super widefield optics provides crystal stereo erect images 2-1/2" (65mm) SUPER widefield of view and 8" (200mm) working distance 3D boom stand allowing point microscope head in any direction desired Trinocular port for adding photo/video capability