Offers a continuous range of magnification, allowing viewers to "zoom in" and "zoom out" on specimens to achieve the optimal magnification. Ideal for serious scientific research, medical, forensic and other high end, higher-powered stereo uses, trinocular, boom mount. Baytronix 7x - 45x Stereo Zoom Binocular Microscope, Dual Variable Halogen Lighting Sytem $512.00 Baytronix 7x - 45x Stereo Zoom Trinocular Microscope, Dual Variable Halogen Lighting System $542.00