[MEASURE REFRACTIVE INDEX] Specially designed for accurately measuring the refractive index of gemstones and solid materials.[PORTABLE AND ] 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.high accuracy and easy operation.Identify single and double gems quickly and precisely.Low battery consumption for long service time.Approved by quality and safety standards for a long and trouble-free usingColour:BlackMaterial:plasticPackage Contents:1 x Refractometer1 x Electric Torch (Powered by 1 x AA battery which is NOT included)1 x 3 ML Reflective Index FluidOnly 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.