The AmScope SW-3B13X binocular stereo microscope head has a pair of 10x20mm widefield high-eyepoint eyepieces a 1x/3x objective a 0.5x Barlow lens and a single-arm boom stand. The microscope head has a 3 O-ring style mounting ring. The binocular viewing head has an interpupillary range of 47 to 75mm a 45-degree inclination to reduce eye and neck strain and 360-degree rotation to enable sharing. The WF10x20mm super-widefield high-eyepoint eyepieces combine with the 1x/3x objective to provide 5x 10x 15x and 30xmagnification and a longer working distance for inspecting large-scale specimens that require handling or repair. The microscope includes a 0.5x Barlow lens that can be added to the objective to decrease the magnification range. A Barlow lens with a magnification of less than 1.0 reduces magnification and increases the working distance. High-eyepoint eyepieces ease viewing for users who wear glasses dioptric adjustment accommodates individual eye-strength differences and eye guards ensure comfortable viewing. The optical glass lenses provide sharp images and are fully-coated to ensure high-resolution images. 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. Ambient lighting illuminates the specimen eliminating the need for power or batteries. The microscope has a 17 pillar that has an 8 vertical working distance. The 16 single-arm boom has a 24 overall length. Bilateral focus eases use for left- and right-handed users. The microscope head can be rotated on the X- and Y-axis. The solid cast-steel base is 1-3/4 x 9 x 9 inches (H x W x D where H is height the vertical distance from the lowest to highest point; W is width the horizontal distance from left to right; D is depth the horizontal distance from front to back). SpecificationsHeadBinocularMagnification5x 10x 15x 30xObjective power 1x/3xEyepieces (30mm)WH10x20mmOptical working distanceUp to 4 Field of view0.787 at 10xMicroscope standSingle-arm boom standHead movementX- and Y-axesIllumination typeN/ALight sourceAmbientPowerN/A Microscopes 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. What s in the Box? Binocular stereo zoom head with 1x/3x objective WH10x eyepieces one pair 0.5x Barlow lens Single-arm boom stand with focus rack Eye guards one pair