The BestScope BS-8040B Gemological Binocular Zoom Microscope has a pair of 10x extra widefield eyepieces, zoom body with 1:6.5 zoom ratio, brightfield and darkfield halogen and fluorescent illumination, iris diaphragm, and a gem clamp. The binocular head has interpupillary adjustment, and a fixed inclination to reduce eye and neck strain, and its height can be adjusted to accommodate individual samples and users. Dioptric adjustment accommodates individual eye-strength differences. The zoom body has ample working distance (WD) for examining specimens. A gemological microscope uses transmitted and reflected light to view gemstones.