AmScope 3.5x-90x Stereo Boom Zoom Microscope with Fiber Optic Dual Ring Illuminator 3.5X-90X very large zoom magnification power with crisp sharp images 150W fiber optic halogen ring illuminatior 8" (203D boom stand allowing you to point microscope head in ANY direction desired 2-1/2" (65mm) SUPER widefield of view 8" (200mm) working distance