The AmScope SM-4TZ-144A professional trinocular stereo zoom microscope has a pair of 10x super-widefield high-eyepoint eyepieces a 0.7x-4.5x zoom objective two Barlow lenses and a double-arm boom stand. The microscope has an overall magnification range of 3.5x-90x. 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 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 removable 144-bulb LED ring light has four separate zones to independently control light intensity and direction. The ring light provides bright cool light for working with temperature-sensitive or live specimens and shadow-free illumination. A rheostat controls the amount of light emanating from the lamp. Power and adjustment controls are located on a control box to speed adjustments. The ring has a 2-1/2 (64mm) inside diameter and a 4 (100mm) outside diameter. It has a 100 000-hour life span and a 110V-240V variable power supply. The microscope has a double-arm boom stand that enables users to position the microscope head on all three axes (X Y and Z). Bilateral focus eases use for left- and right-handed users. The stand has 20 double arms and a 30 overall length. The pillar is 17 and the focus rack has a 3 diameter. The solid cast-steel base is 2 x 8-1/4 x 10-1/4 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). SpecificationsHeadTrinocularMagnification range3.5x-90xZoom objective power 0.7x-4.5xEyepieces (DIN 30mm)WH10x20mm high-eyepointTrinocular portC-Mount or 23mmField of view2-1/2 Optical working distanceUp to 8 Microscope standDouble-arm boom standHead movementX- Y- and Z-axesIllumination typeEpiscopic (reflected)Light sourceFour-zone 144-bulb LED ring light with rheostatPower110V-240V 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