I have had this unopened gem microscope in my garage for several years. Bought from JTV several years ago, I never used it. It has been opened today only for photos and to verify operation. Following is information that I dug out about this unit.
Technical Specifications: Optical Index: Field of View 20mm at WF10X Working Distance: 76 mm Standard zooming range: 10X - 60X depending on which eyepiece is used Auxiliary objective: 1.0X, 3X Electrical: Input voltage 110V/60hz Structure index: Standard Zoom Power: 10X to 30X with 10X eyepieces. 20X to 60X with 20X eyepieces. Inclined 45 degree; binocular head, 360 degree rotatable Left and right eyepiece diopter adjustment +/- 5 degrees, interpupillary distance adjustable 55-75 mm Environmental requirement: Dry, dust-free room with temperature between -5 to +40 degrees C Microscope has Dark-Field Attachment which creates a type illumination pertinent to the identification of gemstones.
Also, Diffused Bright-Field Disc which allows light to enter from below, but the light has been diffused. This allows for easier observation of weak curved striations and weak color-zoning or banding, which are difficult to see in pale colored stones. Lighting above the object, below the object or both is selectable. The item "10X-30X, 20x -60X Binocular Stereo Darkfield Gem Microscope+Jewelry Clip NEW" is in sale since Thursday, March 08, 2018. This item is in the category "Jewelry & Watches\Jewelry Design & Repair\Jewelry Tools\Loupes & Magnifiers".The seller is "print4u1967" and is located in Moreno Valley, California. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Israel, Mexico, New Zealand, Philippines, Singapore, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Chile, Colombia, Costa rica, Dominican republic, Panama, Trinidad and tobago, Guatemala, El salvador, Honduras, Jamaica.