[ Wine Refractometer ] Designed to test the sugar content in original grape juice, then the alcohol level in the wine(which will be brewed from the grape juice) can be known from the scale, and alcohol-content by volume of the grape wine made from the fermented grape juice [ Measuring Range ] Measuring Range:0-40%,Accuracy:±0.2%; Alcohol Measuring Range:1.000 - 1.130,Accuracy:±0.001 [ Easy to use ] Place 2 - 3 drops of sample onto the prism, and then look through the eyepiece for both and proportion readings [ Convenient to store ] Compact in size and light in weight, packed with a plastic case, convenient to store and carry around [ Application ] desirable for Wine Making, Home Brewing, Agricultural, Gardening & Educational Purposes