The AmScope LED-144A stereo microscope illumination system has a 144-bulb LED ring light with 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. The light includes an adapter ring for mounting on a stereo microscope head. It has a 100,000-hour life span and a 110V-240V auto-detecting power supply.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? LED Ring light Control box Mounting ring Power cord