The AmScope SM-2TZZ professional trinocular stereo zoom microscope has interchangeable pairs of 10x and 20x super-widefield high-eyepoint eyepieces, a 0.7x-4.5x zoom objective, two Barlow lenses, and a pillar stand. The microscope has an overall magnification range of 3.5x-180x. The trinocular viewing head has an interpupillary range of 55 to 75mm, a 45-degree inclination to reduce eye and neck strain, and 360-degree rotation to enable sharing. The vertical trinocular port can be used as a C-Mount or 23mm photo port (camera sold separately). The WH10x20mm and WH20x10mm super-widefield high-eyepoint eyepieces combine with the 0.7x-4.5x zoom objective to provide continuous zoom magnification and a longer working distance for inspecting large-scale specimens that require handling or repair. The microscope comes with 0.5x and 2.0x Barlow lenses that can be added to the objective to increase the magnification range. A Barlow lens with a magnification of less than 1.0 reduces magnification and increases the working distance, while a Barlow lens with a magnification greater than 1.0 increases the magnification and reduces the working distance. High-eyepoint eyepieces ease viewing for users who wear glasses, and dioptric adjustment accommodates individual eye-strength differences. A stereo microscope, sometimes called an inspection or dissection microscope, has low magnification and a long working distance that enables users to manipulate the object being inspected.The microscope has upper (episcopic) illumination that reflects light off the specimen for enhanced visibility of opaque specimens, and lower (diascopic) illumination that transmits light up through the specimen for enhanced visibility of translucent and transparent objects. A frosted stage plate allows light to pass through from below with transparent specimens, a reversible black and white stage plate provides contrast with light- and dark-colored specimens, and stage clips secure the specimen during viewing. The 15W halogen light source provides bright light in a concentrated path. The pillar-style stand has bilateral coarse focus to ease use for left- and right-handed users. All metal construction is durable and the enamel finish is stain-resistant. SpecificationsHeadTrinocularMagnification range3.5x-180xZoom objective power0.7x-4.5xEyepieces (DIN, 30mm)WH10x20mm and WH20x10mm high-eyepointTrinocular portC-Mount or 23mmField of view2-1/2Optical working distanceUp to 8Microscope standPillar standHead movementX-axisIllumination typeEpiscopic (reflected) and diascopic (transmitted)Light sourceHalogen, 15WPower110V-120VMicroscopes are instruments used to enhance the resolution of an object or image. Types include compound, stereo, or digital. Compound microscopes use a compound optical system with an objective lens and an eyepiece. Stereo microscopes show object depth in a three-dimensional image. Digital microscopes are used to display an image on a monitor, rather than looking through a lens. Microscopes can have monocular (one), binocular (two), or trinocular (three) eyepieces, with varying magnification abilities. Magnification ability refers to the size of an image. Resolution, also known as resolvant power, refers to the clarity of the image. The interaction between field of view (FOV), numerical aperture (NA), and working distance (WD) determines resolution. Microscopes can control magnification through a fixed focus, or through a range of adjustments. They can also utilize LED, fluorescent, and mirror light sources to help control viewing capabilities. Microscopes are widely used in education, lab research, biology, metallurgy, engineering, chemistry, manufacturing, and in the medical, forensic science, and veterinary industries.United Scope manufactures microscopy equipment and accessories under the brand name AmScope. The company, founded in 1996, is headquartered in Irvine, CA. Whats in the Box? AmScope SM-2TZZ stereo zoom microscope with pillar stand WH10x20mm eyepieces, 30mm, one pair WH20x10mm eyepieces, 30mm, one pair 0.7x-4.5x zoom objective 0.5x Barlow lens 2.0x Barlow lens Focus rack Eye guards, one pair Frosted stage plate Reversible stage plate Stage clips, one pair Spare halogen bulb Dust cover Instructions