Our professional diamond tester combines LCD display with LED indicators for clear, instant reading.This diamond selection tool is designed for fast and safe gem verification, ensuring no damage to jewelry during operation.It is trusted by jewelers, collectors and gem lovers, providing unparalleled accuracy for imitations such as diamonds and cubic zirconium ().Small and user-friendly, it offers extraordinary value as a workplace essential and caring gift for gemology enthusiasts. One-click functionality of Diamond Test Pen simplifies testing.Turn on the device and gently place the probe on the of the stone, waiting for the audio-visual results.diamonds trigger an alarm above and above on the display screen and make a sound confirmation, while non-diamonds (such as glass, ) not respond.Great for quick inspection of rings, bulk gems or vintage jewelry, this gem tester requires no technical expertise - perfect for amateurs and professionals. This gem tester distinguishes diamonds from imitations by analyzing the heat diffusion rate. Metals can trigger error signals due to overlapping conductivity, thus avoiding accidental contact bands or settings.For best practices, test clean, dry gems on the included platform.If the pen is flashing or off, recalibrate the settings or check the probes.Dedicated test surfaces minimize ambient temperature interference and consistent performance. Before scanning, select the appropriate carat mode through the +/- button.The sensor panel is maintained after skin contact to stabilize readings-Improper handling can distort the results.Small and convenient for travel, it is a must-have for auctions, real estate sales or jewelry studios.Store in dry and room temperature environments to extend the life of the probe. Adjust the settings of the diamond selector according to the gem size to optimize accuracy.For gems larger than 1.0 carats, activate a green LED; 0.5 carats requires two LEDs, while complex cut or small gems (such as melee diamonds) require 3-4 LEDs.Place the probe vertically to avoid touching the buttons during testing to prevent errors.Note: Due to similar thermal conductivity characteristics, this thermal conductivity-based diamond tester may emit high frequency alarms on metals - always follow the guidelines to avoid testing on skin, liquids, or non-gemite materials. Color:Black Material:plastic Package Contents: 1set * dimond tester pen Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.