Product Name: Binocular Drawtube Zoom Stereo Microscope 1X-4X Model NO.: XT-300 Principle of Optics: Galileo Optical System Principle: Optics Usage: Research Shape: Cylindrical Shaped Lens Kind of Light Source: Ordinary Light Stereoscopic Effect: Stereoscopic Effect Mobility: Desktop Number of Cylinder: Binoculars Type: Stereomicroscope Magnification: <50X Item: Stereo Microscope Drawtube: Binocular Zoom Ratio: 1:4 Objective Zoom Range: 1X-2X 1X-3X 2X-4X Eyepice: Swf 10X/23mm Working Distance: 120mm Interpupillary Distance Adjustment Range: 55mm-75mm Binocular Head: Inclination of 45