Features: Professional Tester with advanced thermal conductivity technology instantly verifies authenticity through precise heat transfer measurement. Compact ABS built device features a LED indicators systems and portable pen styles design for effortless single handed operate in jewelry verification tasks. Essential tool for jewelers, pawnshop owners, and enthusiasts requiring on site authentication during purchases or collection evaluations. Ideal for quick checks at jewelry stores, exhibitions, or home based jewelry appraisals with fast results displayed through color coded LED signals. Multi functional models extend testing capabilities to popular simulants like zirconia and moissanite, making it versatile for comprehensive identification needs. Specifications: Component: ABS. Size: about. 15.5x4cm/6.1x1.57in Battery NOT include. Package Includes: 1pc Tester Pen note: Please allow 1-2cm errors due to manual measurement. Due to difference between different monitors, the picture may not reflect the item actual color.