NIUNIU Professional Refractometer, Handheld Alcohol Test Refractometer, Wine Tester Meter Measure Instrument This is an professional optical refractometer which is designed to measure the alcohol concentration of liquor. It is not suitable for measurements of the alcohol content in the beer or wine! Place 2 - 3 drops of sample onto the prism, and then look through the eyepiece for both the density of alcohol readings. This alcohol refractometer is lightweight and compact in size, it is very convenient to store and carry around. After use, it is strictly forbidden to wash directly into the water, wipe it with a clean soft cloth. For the optical surface, it should not be scratched or scratched. Colour: Black Size: 16*6*8cm Quantity: 1pc Kind tips: 1.As different measuring methods,it will occur 1-3 cm deviation about the items,please ensure that it is okay for you before ordering. 2. Because of different monitors and lamplight, the picture may not reflect the actual color of the item, really thank you for your kind understanding. 3. Only the above package contents, excluding other products.