Sterling Silver Oxidized 3D Scientific Instrument Microscope Charm Pendant with Box Chain Necklace Oxidized Sterling Silver Charm Height 18 millimeters (0.71 inch) x Width 7 millimeters (0.28 inch) Charm Weighs Approximately 1.1 grams (2.8 grams including 16" necklace) High Polished Box Chain Thickness Approximately 0.7 millimeters (1/32 inch) Spring Clasp on Necklace