Body Type - Binocular 360° rotatable 45° inclined eyepiece tube. Eyepieces - Two 10x(FN20) eyepieces. Optional: 15x(FN15) 20x(FN11.4) available to extend magnification range. Auxiliary lens - 0.5x 0.75x and 1.6 auxiliary lenses available to extend magnification range of microscope. Working Distance - 80 mm. without auxiliary lens 120 mm. with 0.5x auxiliary lens 85 mm. with 0.75x auxiliary lens 41 mm. with 1.6x auxiliary lens. Zoom Ratio - 3.5:1. Diopter Adjustment - On both eye tubes: +5.6D-0.72D. Interpupillary Distance - Adjustable from 52 to 75 mm. Optical System - Greenough. Item Weight - 3.65 lbs.Specifications Body Type - Binocular 360° rotatable 45° inclined eyepiece tube. Eyepieces - Two 10x(FN20) eyepieces. Optional: 15x(FN15) 20x(FN11.4) available to extend magnification range. Auxiliary lens - 0.5x 0.75x and 1.6 auxiliary lenses available to extend magnification range of microscope. Working Distance - 80 mm. without auxiliary lens 120 mm. with 0.5x auxiliary lens 85 mm. with 0.75x auxiliary lens 41 mm. with 1.6x auxiliary lens. Zoom Ratio - 3.5:1. Diopter Adjustment - On both eye tubes: +5.6D-0.72D. Interpupillary Distance - Adjustable from 52 to 75 mm. Optical System - Greenough. Item Weight - 3.65 lbs. - SKU: AVEN675