Instruction: Parse the product information to locate the target attribute, and then provide the extracted value of the target attribute and its source in the output, specifying None if the attribute is not present.

Input:
Product title: 5x-80x Trinocular Stereo Zoom Microscope Dual Halogen
Product description: The AmScope SH-2TZ professional stereo zoom microscope has interchangeable pairs of WF5x, 10x and 20x widefield eyepieces, a 1x-4x zoom objective, and a pillar stand. The microscope has an overall magnification range of 5x-80x. 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 WF5x18mm, WF10x18mm and WF20x10mm widefield eyepieces combine with the 1x-4x zoom objective to provide continuous zoom magnification and a longer working distance for inspecting large-scale specimens that require handling or repair. Dioptric adjustment accommodates individual eye-strength differences. 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. 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 10W 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, and stage clips to secure the specimen during viewing. All metal construction is durable and the enamel finish is stain-resistant., 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.
Product feature: 5X-80X continuous zoom power with sharp stereo images, High quality optical lenses and sturdy metal framework, Incident (top) and Transmitted (bottom) illumination, Heavy-duty pillar stand with extra large base, Trinocular port for adding photo or video capability
Product price: $39.43
Product brand: AmScope
Target attributes: Light Type
Answer: attribute: light type
value: stereo zoom
source: product title
attribute: light type
value: stereo
source: product feature
attribute: light type
value: stereo zoom
source: product description
attribute: light type
value: stereo
source: product description