Intuitive Design, Fast and Safe - Our diamond tester features an LCD display and LED indicators for clear and accurate test results. Designed for fast, precise, and safe testing, it ensures no damage to the gemstone during use. Delivers reliable results every time, making it a popular choice among professionals, hobbyists, collectors, and business owners. A great value tool and thoughtful gift. Easy to Use - Simple one-button operation with clear visual feedback. No prior experience required. Turn on the device, gently place the tip on the gemstone, and wait for the beep to determine authenticity. Real diamonds trigger a signal indicated by illuminated LEDs and an audible tone. Non-responsive results suggest the stone is a simulated gem such as cubic zirconia. Adjustable Settings - Position the pen vertically and apply light pressure to the stone. Use the up/down buttons to adjust the carat range displayed based on the size of the gem. For diamonds of 1.0 carat, one green light will illuminate; for 0.5 carats, two green lights. For smaller stones (e.g., melee or small cuts), three to four green lights may be used. Avoid pressing any buttons during testing to maintain accuracy. Thermal Conductivity Principle - The device operates based on thermal conductivity to differentiate diamonds from imitations. Metals may produce a high-frequency sound during testing due to similar thermal properties, but testing on metal, skin, liquid, or other non-gem materials is not recommended. Important Usage Notes - Always follow proper testing procedures. Ensure contact with the touch panel on the back of the device during operation, as failure to do so may result in incorrect readings. The tester may flash or shut off if improper contact occurs or if used on unsuitable surfaces. Color: As Shown Material: Plastic Package Contents: 1 x Diamond Test Pen 1 x 1M USB Cable 1 x Test Platform Note: Light reflection and screen differences may cause slight variations between the product color in images and actual color. Measurement error allowance: +/- 1-3 cm.