1.This model works for alcohol testing (to test the alcohol concentration in the alcohol solution, not the grape wines or the other fruit wines). Its unit is W/W (Weight/Weight), the refractometers working temperature is suggested at 20C (about 18C to 25C). 2.Measure the alcohol content accurately in seconds All you need to do is manufacture a distillate of the liquids to be measured, and then place the distilled sample on the prism. 3.Measure the alcohol level of thefruit wine; Measuringfruit winein is erroneous because fruit wine contains sugar and other soluble substances that affect the refractive index of alcohol. 4.The specific errorwillvaryfrom the brewing of fruit wine to the brewing of fruit wine. Specification: Measuring range: 0-80%. Minimum unit: 1% Accuracy: 1% Reference temperature 20C size: 19.7 x 4cm Material: Plastic + Metal colour: black + silver Package Contents: 1 x Alcohol Refractometer 1 x Pipette 1 x Screw driver 1 x Cleaning cloth(Note: Random color, don't accept the specified color.) 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.