[MEASURE REFRACTIVE INDEX] Specially designed for accurately measuring the refractive index of gemstones and solid materials. [PORTABLE AND LIGHTWEIGHT] Easy to carry around, perfect for on-the-go identification. [HIGH ACCURACY OPERATION] Features high accuracy and simple operation for precise gem identification. [QUICK GEM IDENTIFICATION] Identify single and double gems quickly and precisely. [LONG BATTERY LIFE] Low battery consumption for extended service time.<br><br>high accuracy and easy operation. Identify single and double gems quickly and precisely. Low battery consumption for long service time. Approved by strict quality and safety standards for a long and trouble-free using Colour:Black Material:plastic<br><br>Package Contents: 1 x Refractometer 1 x Electric Torch (Powered by 1 x AA battery which is NOT included) 1 x 3 ML Reflective Index Fluid<br><br>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.