Trinocular Stereo Microscope with zoom Ratio 6.4 : 1, 7x to 45x magnifications and working distance 100 mm (This is the distance from the lense to the base. Illumination - Transmitted and incident 3W LED illuminations with built-in 100-240V power supply. Both illuminators can be used simultaneously and the light intensities can be adjusted separately Optional (not included in the order) Optional auxiliary lens 0.5X, 0.75X, 1.5X 2.0X. USB CAMERAS OR CCD cameras. For other microscopic things please refer here