These compact refractometers give you a direct reading scale of the concentration of some common liquids. Rugged ip65-rated design is ideal for indoor and field use. Simply apply two to three drops of sample onto the prism, press the start key, and the value is displayed in seconds. Digital display eliminates reading errors common with handheld refractometers. Cleanup is simple - easily clean under running water. Measure concentration of specific liquids with these special-scale refractometers.