Professional Alcohol Hydrometer Meter Tester for Wine, Vodka, Whiskey, Alcoholmeter Measuring Instrument, Measurement Tools with Plastic Case. The scale on the hydrometer reads from 0 to 100 percent alcohol. Includes three hydrometers: 0-40%, 40-70%, and 70-100%, along with one 0-50 degree Celsius thermometer. Alcohol concentration measurements are accurate only at the standard temperature of 20C. When measuring at non-standard temperatures, use the included conversion table to adjust the reading to the equivalent value at 20C for accurate alcohol concentration. Color: as shown. Material: glass. Instructions for use: 1. Clean and dry the hydrometer before use (can be cleaned with soap or alcohol). 2. After cleaning, do not touch the engraved portion; hold the top of the tube gently with fingers. 3. Ensure the graduated cylinder is clean to avoid inaccurate readings. 4. Discontinue use immediately if cracks, paper index displacement, or unremovable surface dirt are observed. Note: This set is primarily intended for measuring alcohol concentration in distilled spirits. For most accurate results, measure at 20C. Not suitable for measuring non-distilled or fermented liquids. Package includes: 3 x Hydrometer (alcohol meter), 1 x Thermometer, 1 x Plastic Case, 1 x English Manual. Light and display differences may cause slight color variations. Measurement error allowance: +/- 1-3%.