Lighted Loupe Magnifier Inspection Supplies Optical Lens. Illuminated 20X High Powered Magnifying Glass Loupe, with 21MM Diameter Optical Glass Lens. Teardrop loupe has a crystal clear viewing lens, compact folding capability with screw pin holds, On-Off LED slide light switch, battery compartment lock key, slotted end for key chain or chain attachment, silver metal construction, and case included. Magnifier Eye Piece is a nice size hand held pocket Loupe. Requires 3AG7 Batteries (Batteries Are Included.)Inspection magnifiers great for jewelers diamond inspection, Lighted Teardrop loupe also used in geology and biology Inspection magnifiers great for jewelers diamond inspection , Lighted Teardrop loupe also used in geology and biology Labratory lab supplies to research inspect mineral , plant , and insect identification. laboratory, lab supplies to research inspect mineral, plant, and insect identification .