1. Accurate measurement based on good calibration, please calibrate the refractometer before your first use. 2. Please keep the refractometer dry and clean for the instrument to be accurate and durable. NOTE: Not recommended for wine or others that are high in sugar and other ingredients. 1. EASY AND FAST MEASUREMENT Alcohol Refractometer for testing alcohol-alcohol volume percentage for brandy, whiskey, vodka, etc. NOTE: Not recommended for wine or any other product that is high in sugar and other ingredients. 2. ACCURATE READINGS WITH ATC: Handheld alcohol refractometer with automatic temperature compensation (ATC), no more worry about the temperature change affecting the reading accuracy. The refractometer for measuring the percentage of alcohol by volume takes into account changes in the ambient temperature and automatically compensates for them accordingly to enable accurate and repeatable measurements. 3. Endless use: It is a portable optical instrument for bartenders, alcohol dealers and food manufacturers, etc. The scale range is 0 - 80% V / V (V / V - alcohol volume in percent), division: 1% v / v. 4th Metal + Plastic: The alcohol refractometer is made of non-staining, non-corrosive and non-reactive aluminum, which is easy to carry, scratch-resistant and durable. 5. NOTE: Not recommended for wine or anything high in sugar or other ingredients.