The Krüss Stereo Zoom Microscope has precision optics for examining diamonds and gemstones. Features: • Zoom magnifications form 7x to 45x • 10x eyepieces • 3.5" (90mm) free working distance • Built-in illumination for reflected and transmitted light • Darkfield illumination for observation of inclusions • Stoneholder for set and unset stones • 110 Volts (220 Volt model available on special order) • Warranty for 2 years on optics; 1 year on electrical parts Optional 20x oculars increase magnification to 14x - 90x.