This is a 3.5X-90X zoom magnification trinocular stereo microscope head. It includes two Barlow lenses (0.5X and 2.0X) a pair of super widefield high-eyepoint 10X eyepieces and foldable eyeguards. It comes with 45-degree inclined 30mm eyetubes with diopter. Its trinocular port enables to add photo or video capability. The microscope provides sharp clear erect stereo images over a large zoom magnification range. Its super widefield optics and high-eyepiont design ensure an easy and comfortable observation. This microscope head fits all the stands with a 3inch (76mm in diameter) O-ring holder. It is made by the same technicians and on the same production line that makes optical instruments for Leica Zeiss Nikon and Olympus. 3.5X to 90X Continuous Zoom Magnification Power 45-degree inclined Trinocular Head with SUPER WIDEFIELD High-Eyepoint Eyepieces 30mm Super Widefield WF10X/20 Eyepieces High Resolution with Great Flatness and Contrast Sharp Stereo Erect Images over a Wide Field View Crystal Clear Original True Color Images Both Ocular-Tubes with Adjustable Diopter 8inch (200mm) Large Working Distance Accurate Alignment Ensuring a Fatigue-Free Viewing Full Optical Glass Elements Precise Ground Glass Lens All Metal Mechanical Components Adjustable Interpupillary Distance Rubber Eyeguards Included Eyepiece: 30mm super widefield high-eyepoint WF10X Barlow Lens: 0.5X Objective: 0.35-4.5X Zoom Range: 13:1 Interpupillary Distance: 2-0.75inch - 2-15/16inch(47-75mm) Field of View: 2-0.5inch (65mm) Working Distance: 8inch (200mm) Head Mounting Size: 3inch (76mm) in diameter Accessory Mounting Size: 1-0.875inch (48mm female thread) in diameter Type: Stereo