Features: Heavy-duty and lightweight with its aluminum construction High quality and accurate testing results are guaranteed Equipped with Built-in ATC compensation Range (Automatic Temperature Compensation) from 10 to 30 to correct temperature discrepancies during use Easy to focus & calibrate and very convenient to use Durable and built to last long Comprehensive operations manual, complete with soft & protective carrying case, pipette and mini-screw driver for easy calibration are provided for user's convenience and comfortability This Alcohol refractometer is designed for the measurement of distilled beverages (ethanol with water) like whiskey, brandy, fruit brandy, slivovitz, vodka, gin, tequila, Chinese alcohol, etc. It has a scale in the range of 0 - 80 % (VOL - alcohol volume percent). Specifications: Measuring Range : V/V 0-80% Minimum Divisions : V/V 1% Accuracy : 1% Length : 180mm Weight: 164g Heavy duty (Durable Aluminum) How to Use 1. Align the Cover Plate with light, adjust the Focus Adjustment until you see the scale clearly. 2. Calibration: Accurate Measurement depends on careful calibration. Please make sure the ambient temperature is about 68 F, distilled water can be used to calibrate. Open the Cover plate. place 2-3 drops of the distilled water on the prism, then close the cover plate and make sure the water spread aro the prism without any air bubbles or dry spots. wait for about 30 seconds to let the reading to stabilize. Look into eyepiece and turn the calibration screw with the screw driver until the reading is "0" 3. Clean the prism with soft cloth, then place 2-3 drops of the liquid sample to be tested on the prism.then close the cover plate and make sure the water spread aro the prism without any air bubbles or dry spots. wait for about 30 seconds to let the reading to stabilize. Align the prism aembly with the light source. look into eyepiece and you can get the reading. 4. Please leep the refractometer dry and clean in the box, which can make sure the reading accuracy and durable. Package Content: 1 x Refractometer 1 x Pipette 1 x Screw driver 1 x Cleaning cloth 1 x English Instruction manual 1 x Box